Art Connoisseur: Buy a painting from Florence and Venice. 10g. Ubisoft Montreal obviously takes a lot of consideration in their setting, story and content. I guess it's just natural that they'd want to include some of the art of the time. What pieces will we see?
Steal Home: Win a race against thieves! 10g. I like the idea of side-mission variation as much as I like the idea of main-mission variation and races can certainly fit into the world of AC.
Doctor: Perform an Air Assassination on a Poisoned NPC. 20g. I like achievements like these a lot because their easy to do, they sound like they're easy to do, but they only end up taking a handful of tries before you eventually get it right. Not like that goddam Mile High Club achievement.
What AC II achievements interest you?