the firs Souls i played was Demo's, in 2010, and i have to say, the game was fantastic! At first a hated it, the game was merciless, and I just could not progress, and then gave up and cursed the game! But the story does not end there ... I walked away from the game but could not stop thinking about him, one week after I got back, deleted the character and started from scratch, and it started to progress and I started to feel something new that not felt a long time, something forgotten, coming from the time of my childhood ... it was real challenge and pressure from a game ... PS2 era, and most "PS360wii" era, a time of easy games for me, fun but there was no challenge, no feeling that I felt as a child playing Majoras mask, Ocarina of Time, Diablo II, Mega Man, Sonic, Donkey Kong, Demon's Crest, Mario, Chrono Trigger and several other games that were a major challenge in my childhood ...

I had forgotten that good feeling of challenge, and Demon's Souls awakened this in me again! That's why I love this series, it has the old school elements that make me feel how I felt as a child, playing a tough game that needs all my concentration!
Similarly, Dark Souls could also cause the same impact on me, I say, further, that Dark Souls surpassed "Demon's Souls in my view, especially at the beginning, before they "put sugar" in the game with Patches that made the game easyer (but do not get me wrong, the game was still an acceptable challenge)

Then came dark souls II, I must say I was a little disappointed ... I mean, the game is still very good, worthy of the name souls, but does not compare to Demon's / Dark I.
Dark souls II is a fantastic game, I really liked it, but it did not have the "magic" of its predecessors ...

Now comes bloodborne ... and I hope ... and wait ... for a even better experience ... Umbasa.

For know my rank is, DSI> Demon's >> DS II

Dark souls is my favorite.
What I love most about the series is exploring a handcrafted fully interconnected world at a slow careful pace. Dark souls did that the best with its world design. I'm a little hesitant about Bloodbourne putting the focus on more fast paced combat, I'm afraid that's not my style. I'm more into keeping my distance, luring them out, and using magic, bows and traps.
But I'm willing to give Bloodbourne the benefit of the doubt, although the Eurogamer preview I just read about the combat changes only makes me less excited. It's probably for the better to go in with low expectations, maybe that way it will surprise me again as Dark souls did, while DS2 could not.

I have Demon's Souls installed on my PS3 but I'm still hesitating about starting it. How long does it take to finish it? I'm not sure if I care enough to finish it, let alone get the platinum :-/

It's really hard to say, it depends really on your playstyle and how quickly you learn to play. It took me about 60h for first playthrough but I'm very conservative, second playtrough took me about half of the time (with a different class, not New Game +).

First time > nothing less than 30h. If you played DSI, than you will do fine, perhaps can end things in a bit early, but i still think it will be something like 30-40h at least.

second time> the games is like old school Zelda whit no "Required dialogues", the much needed skip button from old zelda games. I can finish it in 8-10 h, it's a good and fun day, create a character a beat Dark/demons souls in 1-2 days.

my first play through was ~70 hours, my last ~ 3.5 hours (without really trying to be super fast), so it really depends a lot on your play style and what you want to do in the game

if you just want to play through it shouldn't take you long, I just couldn't resist grabbing all the loot (it's glowing invitingly from afar in Souls games) and I overleveled and did all "side quests" I could in my first run

As I have said before, Demon souls is my favorite but I did like dark souls as well. Maybe it has to do with being the first game but both were brilliant nonetheless. Can't wait for bloodborne especially after years of old habit which I read it doesn't work on the game.

This is very interesting, indeed. What's the thing that you love most of Dark Souls 2 to put it first, admist the other two gems?

Well i like all three, but I found DS2 to have the best boss fights, interesting world and defined gameplay. It just seems to get alot of hate for not having a connected world like DS. I dont mind that at all.

Fantastic series overall, but I love DS1 the most. Best overall world.