Just Cause 2 is good but its effect looses touch after a short while, sure you can do all the stuff but It got boring after a few hours of gameplay and the story is the worst thing in the world, repetive stuff too and the DLC they are bringing out is lame, I dont want extra cars, there are already thousands.
I would recommend Conviction, although the story is short it has some really good multiplayer moments and the DLC there are bringing out is ok, I mean I like getting new weapons and armor etc.
If you like stealth games (not as stealthy as the previous Splinter Cells) with Co-op and a good fanbase behind it get Conviction. Also has a good story too.
If you like free-roam and running about doing stunts and blowing shit up, get JC2.