4!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! and no online. resident evil is not an online game, besides some dreamcast I think. outbreak, wasn't it?
while UC is a good game, it lacks, the Replayability and REal fun/Brilliance factor of RE4
RE4 can be enjoyed by many over a longer period of time
But
RE:UC has a fun co-op, but way shorter life.
but if you go for RE:UC make the most of it and but Links crossbow training aswell for a measly 20 pound, and its a great game, with the zapper which works gr8 with UC
but still i would go For RE4 even if you did go for the other 2
RE 4 is older and was available on GameCube and PS2 so make sure he hasn't beat it already. RE UC is newer and much different because it is "on rails" like an arcade shooter. You can't move the character, he automatically moves for you. RE4 is the better game for a gamer where as RE UC is better for more casual play. RE UC also has multiplayer, if your son has anyone to play with... Also this game is not for children.