I have played the vast majority of them. Medieval 2 was, in my opinion, the best ever released in proportion to the time it came out. I really hope they make a 3rd one with an even more complex religious/assassin system. Politics and religion are a lot of fun in the medieval series, in particular.

As for modern ones, nothing beats Warhammer 1/2. They have changed quite a bit, but in a mostly amazing way.

Given that Medieval 2 Total War is the best in the series and Medieval 2 also has the best unofficial Total War with the total conversion Third Age Total War - also the best LOTR game ever made - Medieval is the only objectively correct answer.

Medieval Total War is the best series. While Medieval Total War and Rome Total War were my favorites and somewhat on par, Medieval Total War 2 was vastly better than Rome Total War 2. I can enjoy both games in the series today, despite their age. Modern Total War hasn't been my thing, but maybe someday.

Tough call between Rome and Medieval. I feel they butchered the last Rome with how Attributes are attributed (you can choose them yourself, which should absolutely not be the case), but with Total Realism and Babaorum mods for the very first one pushing it to first spot for me.

Warhammer by far! Probably my favorite pc game!

Haaa. Big Total War fan base here on VGC judging by the votes. I watched a friend play one on his PC around 2008 for about 10 minutes. It looked very cool to be sure, but that's my total experience with the series.

Loved Empire, Rome 1 and 2 and Medieval 2. Didn’t really care for Napoleon for some reason and have only played Shogun 2 for like five minutes. I was interested in Three Kingdoms, looks good, but I don’t think I’ll ever have the time. As far as expansions go I loved Alexander, liked Barbarian Invasion but didn’t care for Kingdoms. Haven’t played any of the other games’ expansions.

Anyway it’s tough; I probably played Empire the most, but had the most fun with Rome 1, and think Medieval 2 is probably the most well-rounded, solid entry.

The fun part is the most important though, so I’ll give this to Rome. Still hoping for a Medieval 3.

Whoo boy, having played them for thousands of hours and even working on mods for some of them, this is a difficult thing to answer. 

- Rome Total War

The one that got me into the franchise. The time it came out I had tried out the demo where you play as Hannibal. This demo made such an impression on me, that I continued to play the game for 3 years solid every weekend and some schooldays.

It was this demo: https://www.youtube.com/watch?v=203P0lBzqGA 

- Medieval II Total War

Crusades? Mongols? I mean come on. It was fucking awesome and fully improved upon previous iterations. I love all its expansions. Especially the Teutonic campaign was incredibly fun. NA'AM SULTAN!

- Empire Total War

This was the one that really got me deep into it. So deep that I started making mods myself. Portrait/name changes, new units, colour corrections and some texture changes. My god I loved it. I also loved the American Revolution angle to it and how it was a big big campaign map. 

- Napoleon Total War

This came out in a period where I got really into the whole French revolution leading up to the Napoleonic wars. Played for thousands of hours and again working on mods. To be fair, this game is best with some of the mods out there that frees up more factions in campaign. 

- Shogun 2 Total War

Criminally underrated game, it got especially good during the later turns of campaign when more modernized weaponry are introduced. Kinda gave me hope for a possible WW1 game. Also, who wouldn't choose the Satsuma clan with their Triforce flag?

- Rome II Total War

Pretty crappy launch, missing family trees and lots of bugs. Kinda lost faith after this one although... I did revisit the game a year later when they had finally fixed most of the problems I had with it. After that had a blast with it. 

The rest... I kinda lost interest because the settings didn't do much for me. I like Warhammer but honestly I like it more for space battles and whatnots. The newer ones.. same thing. Not interesting in the era.

I don't think I can answer this. I've only played Rome, Shogun 2, Attila, and Three Kingdoms, so no Medieval for me (yet). Rome is fun at first but once your empire grows, it gets pretty tedious. Shogun 2 is very nice but real divide is an extremely poor mechanic and it's ridiculous how everyone's spamming naval threats all the time. I especially hate the naval threat because you can either let armies land and then have to deal with them, or you have to chase them around at sea, which requires very annoying micromanagement. Attila seems very good, but I'm still not far enough in the campaign to be able to make a proper judgement. Three Kingdoms is very good in many ways, but there are some flaws too that make me think that Medieval 2 might be better (judging by what I've heard).

From the games I've played, I suspect Attila is the best but I can't be sure just yet, Three Kingdoms is probably my favourite from the ones I can judge, but I suspect Medieval 2 is the best but I haven't played it yet.