I've only played the ones made by From Software.  Here is my ranking so far:

1) Dark Souls
2) Dark Souls 2
3) Dark Souls 3
4) Demon's Souls
5) Bloodborne

1. Dark Souls 2
2. Bloodborne
3. Dark Souls
4. Demons Souls
5. Nioh
6. Dark Souls 3
7. Lords Of The Fallen
8. The Surge

EDIT: I forgot about Sekiro. Not a game for me, but I can see why people think its great.

Nioh (if counts, but tbh it is quite different.)
Dark Souls 3
Demon's Souls
Bloodborne
Dark Souls
Lords of The Fallen

I have Sekiro, Nioh 2, and Elden Ring on my list. Maybe Code Vein for cheap.

1. Sekiro
2. Dark Souls
3. Nioh
4. Dark Souls 3
5. Dark Souls 2
6. Demon Souls

Sekiro really revolutionized the combat. I haven't played Bloodborne yet. Nioh was a great and fresh take on the genre, but had too much loot and RNG to make it as good as Dark Souls 1.

On a side note, has anybody played Code Vein? The game has okayish to goodish reviews, and I'm a sucker for Souls likes. 

This is one of my fav series. I dont know what constitutes a "soulslike game" cause I see that term being thrown a lot even with games that dont really feel that much alike (at least to me) like Code Vein or Remnants of the Ashes, so Im gonna stick with the classics.

1 - Bloodborne

2- Dark Souls

3- Dark Souls 3

4- Demon Souls

5- Sekiro

6- Nioh

7- Dark Souls 2

For me, Bloodborne is the peak of both gameplay/lore of these games. The fast paced gaming mechanics beats  the  other Souls games every day of the week. The lore is fantastic and the victorian setting and design is just amazing. Not only do I consider it the best of the series but also one of the best games of the generation.

Dark Souls and Dark Souls III follow cause to me they are the standard of the series. Quality boss design, mechanics, good world building and scenario design. Im just edging 1 over 3 because the characters/bosses involved have more importance for the lore. Demon Souls follows them because I feel it it didnt  age as well and the gameplay does feel rough.

I didnt like Sekiro that much solely because its way too rigid with its gameplay, something I dont particularly appreciate. Fromsoft had me accostumed to be given options instead of forced to play a certain way. I didnt like the inclussion of skills in the way it did. And Also i felt many bosses didnt really have the same lore weight as others. Fighting Owl and Isshin is great. Fighting the headless gorilla twice or the corrupted monk twice? Ehhh... Not so much

Nioh is a subpar experience. Many enemies feel exactly the same. The main story didnt really grab me. But some bosses are great. I loved Nue for one, that was my first wall.

I have similar opinions of Dark Souls 2, the lore didnt feel as interesting. Has too many bosses that are irrelevant or shitty. Way too many bosses in general. Not a bad game, but its def. The one that stands out the least for me. 

Dont @ me

Souls 3

Souls 1

Demon

Souls 2

Bloodborne

And Sekiro is utter ****ing trash.

Souls is my second favorite franchise, second only to Zelda.

I did play all of these games not too long after they were released, so part of it is the impact they had when I first played them.  But it is also more than that.  Demon's Souls is a game I really loved when I first played it.  But then Dark Souls came along and I was like, "Wow, this is amazing".  It was just a huge step up from Demon's Souls in every way.  Especially in that, Demon's Souls felt like a game with interesting combat and levels, while in Dark Souls I felt like I was on a journey through a fantastic and diverse world.  Dark Souls was greater than the sum of its parts.  When I went back and played Demon's Souls it just couldn't hold a candle to Dark Souls.

When I played Dark Souls 2 and 3, they were both games I really enjoyed, but they also kind of felt like the same type of experience I got from Dark Souls 1 (maybe slightly worse).  So they get a minor ding against them for not being too ambitious.  I might have to go back and play #1 again, but I do remember liking it the most, at least when I first played it.  

Bloodborne is the only game on the list I didn't finish.  I just don't like the gameplay of it.  One of the biggest reasons I play Souls games is all of the character/combat options and Bloodborne takes a lot of that away.

1. Dark Souls
2. Bloodborne
3. Dark Souls III
4. Dark Souls II

Dark Souls is my favourite, largely due to its impeccable atmosphere, world building and design. I replayed Bloodborne earlier this year and as a result it rose above DS III on my ranking, though I consider the two almost equal, masterpieces both. Dark Souls II is the weakest in the series, but still an excellent game. Just one with more issues than the others. Unfortunately, I haven't played any other 3D soulslikes yet, but I have Nioh sitting on my shelf waiting to be played, and I'm planning on getting Code Vein at some point. The Surge and Lords of the Fallen never appealed to me, the latter looking and feeling like a cheap Dark Souls-ripoff, and the sci-fi setting of The Surge just not doing anything for me, so I've never played them.

Demon's Souls > Bloodborne > Dark Souls > Dark Souls II >>> Let it Die

DS2 still is a great game, Let it Die is just OK - I also played the NioH alpha/beta, which was great, and the Code Vein demo, which was meh

I'm honestly kinda shocked at how many people seem to like Dark Souls II. I just recently finished it for the platinum trophy and hated every minute of it. Well, almost every minute of it. Seemed like difficulty was the name of the game but it was hard for all the wrong reasons; it was almost like a wholly different team to the first game made it without understanding the design philosophy behind why people loved Dark Souls so much! (Yes, I know this was exactly the reality of the situation as Hidetaki Miyazaki made Bloodborne instead of Dark Souls II).

My rankings:

1 - Bloodborne - Not perfect from a technical standpoint but I've never played a game that was so unique, interesting, and deep before. Everything about Bloodborne made me giddy, including the metroidvania styled main game, the sequentially semi-linear Chalice Dungeons, the fact you can play it strictly as a 'get to the next level and beat the boss' perspective or from a 'I care deeply about the lore and story but have to work for it' perspective. I love its art direction, I love how so much of the game's lore and world is labyrinthine and obtuse. I love that you can beat the game without even knowing about 75% of what the game offers, making most of it semi-optional. I love the world building! I love pretty much everything but the occasionally chugging framerate and the loading times. Above all else, I love, love, LOVE the bosses, combat, and world design. One of my all-time favourite games. 9.7/10 - Platinumed

2 - Sekiro: Shadows Die Twice - I know a lot of people hated how they took away much of the RPG elements of this game...but it's not an RPG. IT's a character-driven action game with a far more straightforward story. I love the aesthetics almost as much as bloodborne, I love the world building and design almost as much as Bloodborne, and I think the game runs much better with better loading times. I don't like the lack of variety in weapons, but it's made up for by the finely tuned, near-perfectly crafted combat gameplay and the subtle differences in play styles thanks to the stealth and jumping and prosthetic upgrades. they sacrificed variety and choice but made up for it in a far better crafted combat system. The bosses are also some of the best in the genre, with the addition of minibosses a lovely balance for the relatively low number of main bosses. 9.6/10 - Platinumed

3 - Dark Souls 3 - Honestly, I just felt that of the souls games, it was basically 'what if Dark Souls I had more refined combat, better bosses, better graphics, better performance, and a whole lot of fanservice?" It lacks a bit of the world interconnectivity, but it also doesn't have nearly as many bad bosses, bad areas, or performance issues. The game played smoothly for me, had some of the best DLC and bosses I've EVER played, and..yeah, it's basically Dark Souls I in terms of design philosophy but with a bit more linearity and a whole lot more polish. 9.5/10 - Platinumed

4 - Dark Souls - I absolutely love this game and agree with every good thing ever said about it, but I also think it has a handful of problems that put it below the other three. sure, it was revolutionary, but it had some serious problems with performance (Blighttown, anyone?), some archaic design that went TOO Far off the deep end in terms of obscurity, and a few too many bad bosses and bad areas. I do love the game, but a lot of it came because the game grew on me and I learned to just sort of ignore or accept the bad parts of the game. While it had some of the absolute best bosses in all of gaming and is responsible for some of my favourite gaming moments (Besting Ornstein and Smough, for example), for every outstandingly memorable part there's a shitty boss or area to counterbalance it (Lost Izalith/Bed of Chaos.) I admit I'm being generous with Dark Souls 1 given my critique of it (As I said, the good parts are so transcendently good I mostly just ignore or gloss over the bad parts so they bad has less of an effect on my enjoyment overall), but you know what? I still love this game. 9.4/10 - Platinumed

5 - Demon's Souls - Never beat this game but I did make it about 2/3 through the game before I Started writing game reviews for this very website back in, I think, 2011. At that point, I started playing the games I wanted to/could for review and never finished it. I loved every minute of it, but after playing all three Dark Souls games, Bloodborne and Sekiro, I've decided I don't think I can return to this one without some sort of modern generation update. Too many obscure gameplay mechanics and annoying quests for super hard-to-farm weapons and items. I liked this game, but not enough to finish it and get the platinum trophy. 7.2/10 - No Platinum

6 - Dark Souls II - (More specifically, Scholar of the First Sin.) I platinumed this game but hated every minute of it. After getting all the trophies and beating all the bosses and DLC in Dark Souls Remastered, Dark Souls III, Bloodborne, and Sekiro, I felt I had an obligation to play this one. I had tried before (After beating 1 and Bloodborne and wanting MOAR like this), but I never liked it. After Sekiro came out and I got that platinum trophy, I Felt I had no excuse so I went for it. I hated almost every minute of it. I didn't like the graphics, I didn't like the world design, I didn't like the design philosophy, I didn't like that dodge-rolling was useless unless you arbitrarily upgraded a specific stat (Bloodborne made me a dodge-roll king, and that strategy worked in all other games sans Sekiro), I hated almost all of the bosses and areas with absolutely none of the bosses or areas standing out as being particularly good. The world didn't make sense to explore, the healing and health system were trash, and the game's primary goal was to throw a dozen enemies at you to make the game difficult. I could write a 20k word rant on this game (In fact, I got 10k into it before I gave up due to frustration remembering all the shitty things I hated about this game), but let's not do this here. I liked a handful of things in the game, but too much of it was poorly implemented or overshadowed but just so, so, SO many terrible decisions. 2.4/10 - Platinumed

(For the record, Dark Souls II is now in my list of 'absolutely abhorrent games from otherwise great franchises alongside Final Fantasy XIII, Mega Man X7, Grand Theft Auto IV, Assassin's Creed Unity, etc. It's my second most hated game just beneath FFXIII).

I have also played Nioh and Salt and Sanctuary, but didn't get far enough in either to really form a proper opinion on the game.