Of all time? Theres too many to pick one
Killzone all 3
GTA vice city and san andreas
Super Mario World
this pc game called Empires Dawn of the Modern World (dont play that anymore though but i played the crap out of it)
Thats because some of these games had something the others didnt and i had a different kinda fun with each
I honestly don't think I could pick just ONE game as my favorite. The most I could do is perhaps favorite game series, but even that is a tie between Kingdom Hearts and Fallout. I do love some Mortal Kombat as well....this is harder than I thought. I'll just go with a three way series tie between Mortal Kombat, Fallout, and Kingdom Hearts.