I think ACII was the best in the series. ACI was good, but I will argue that ACII vastly improved several features that needed improving from ACI.
1. An interesting main character that had personality, style, and far more interesting reasons to go kill people (Ezio vs Altiar). Basically, better story telling.
2. Better pacing. ACI lagged on and on with needing to systematically gather evidence the same way every time, grab all towers, help all citizens being harassed, and when the zone was clear, go kill the target and get a long monologue, rinse and repeat. ACII by contrast sped things up and had more options with mission achievements that made you feel like you had accomplished something meaningful and did not drag the game down.
3. Better climbing mechanics. Altiar was a stiff old man with lead arms compared to Ezio.
4. Swimming
5. Even better graphics
6. A more interesting setting
7. Better and more exciting Assassination options... as opposed to the "chase the bad guy while avoiding his buddies to hidden blade him when you get close enough." (although there was plenty of that in ACII as well)
8. Better logic puzzles and level design
9. Better Desmond
10. Better (but obviously still not perfect) AI.
1. An interesting main character that had personality, style, and far more interesting reasons to go kill people (Ezio vs Altiar). Basically, better story telling.
2. Better pacing. ACI lagged on and on with needing to systematically gather evidence the same way every time, grab all towers, help all citizens being harassed, and when the zone was clear, go kill the target and get a long monologue, rinse and repeat. ACII by contrast sped things up and had more options with mission achievements that made you feel like you had accomplished something meaningful and did not drag the game down.
3. Better climbing mechanics. Altiar was a stiff old man with lead arms compared to Ezio.
4. Swimming
5. Even better graphics
6. A more interesting setting
7. Better and more exciting Assassination options... as opposed to the "chase the bad guy while avoiding his buddies to hidden blade him when you get close enough." (although there was plenty of that in ACII as well)
8. Better logic puzzles and level design
9. Better Desmond
10. Better (but obviously still not perfect) AI.