I recently finished Assassin's Creed III, and I thought I'd take a few minutes to share what I liked most about each of the past AC games. Nothing special, just thought I'd post something positive on Destructoid for once. There's far too much negativity out there these days; a newcomer could be forgiven for reading all the comments and thinking none of us actually enjoy playing video games.
Assassin's Creed (2007)
The first game in the series lacked a lot of features they added in the later games, but it did have one advantage over the rest: planning out each of your kills. I loved completing all of the investigatory missions, using the information I had gleaned to lay out a plan of attack, and plan an escape route passing by citizens I'd saved, before finally heading out to kill each Templar. It's something I've never seen in any other games, really. I would love this sort of gameplay to return to the series.
Assassin's Creed II (2009)
The second game added an economy, which made the game world feel much more alive. However, what sets it apart from the later games, I feel, is the presence of Leonardo da Vinci. Using his inventions made the game feel more interesting to me, because I've always been a fan of speculative fiction.
Assassin's Creed: Brotherhood (2010)
The third game's biggest improvement was the main enemy, Cesare Borgia. He's the kind of character I love to hate. In comparison, I can't remember any of the targets from the first, second, or fourth games. Also, Renaissance Rome was more fun to explore than any of the other cities, simply because it had more landmarks that I was able to recognize (of course, other people may feel differently).
Assassin's Creed: Revelations (2011)
Revelations had three high points for me. The mission where you have to protect Suleiman without him knowing while you are dressed as a bard, poorly singing tales of Ezio's past achievements to distract the guests while your comrades take out Templars was amazing. The ending was actually a happy ending with finality. It actually made me smile to realize Ezio got a "happily ever after," which is unusual in video games. Also, Ezio is like sixty years old in Revelations and is still the deadliest guy in Europe. The entire game was like Red where you play as Bruce Willis.
Assassin's Creed III (2012)
The best part of the latest game is the revamped combat system. No more waiting to counter, not to mention having to deal with enemies shooting at you by using human shields. Combat simply felt more, for lack of a better word, kinetic. That said, it's still my least favorite of the series.