Personally, I think a five word limit would be more hilarious, so I'll do that (as a bonus, it technically falls within your five sentence limit as well, so everyone is happy!)
Just Cause 2
Hispanic Superman Blows Shit Up.
Bioshock
Underwater City Goes Completely Bonkers.
SimCity
"Muha ha ha ha" - EA
Crysis
Holy Fuck, So Damn Pretty!
Fallout: New Vegas
Amazing Game With Many Bu-gsg-=--sgssidus-gdgfoia#@$#A#@%JAEF<ERROR - FALLOUT: NEW VEGAS IS NOT RESPONDING>