Which game to rent?!!

so i am going in tonight to rent a game, but i don't know which one to get and i am only allowed to get one, so basically i am just seeking advice to know which of these games would be the best to play for a week:

Mass Effect

Rainbow Six Vegas

Assasins Creed

so i am going in tonight to rent a game, but i don't know which one to get and i am only allowed to get one, so basically i am just seeking advice to know which of these games would be the best to play for a week:

Mass Effect

Rainbow Six Vegas

Assasins Creed

nelso13

You could probably beat AC in a week, but not ME unless you go on a complete and total gaming marathon (or skip all the side quests). I don't know much about RSV but you could probably beat the single player campaign and get a little online time.

okay thanks and i will probably get Mass Effect and Assasins Creed for xmas so im just renting these games for a bit of fun until xmas!