What is better just cause 2 or splinter cell conviction

both are awesome so really it's kinda' hard to choose

But it depends on what kind of game you want. If you're into stealth games with a straight plot and no curves or bends or sandbox, go with SC: conviction.

However, JC2, being an open world game provides a different expeirience altogether. An enormous open world, hilarous voice acting, plenty of game aspects and such. (I really only know about JC2, but I'd chose JC2 over conviction.)