OK now....

me and my friend are playing through a few cheap, fun, online and co-op based games. we have a list in which we expect to go through, and can't decide which to get next.

GRAW 1, Rainbow 6 Vegas 1, and Saints Row

We would like a balance of FUN, EASY-ISH ACHIEVEMENTS, and ONLINE PLAY.

Which do you believe fits those catagories best?

Thanks.