I say Infamous because I got a ps3. Halo3 and Infamous are different games. Infamous is like spiderman but much better ^^. Halo3 is a shooter? Different genres. It's just what you like.
I reckon 'Prototype' will be better than 'Infamous'. Graphics look slightly better, and to be honest, I'd rather rip people to pieces than electrocute them...
ive played both they aren't games that are the same at all in infamous you have a "superpower" lightning ps it is fun. and halo is a futuristic shooter which is also fun
Halo offers both online and offline gameplay while InFAMOUS offers only a single player. Graphics go to Halo aswell, InFAMOUS is grea and all, but when you compare the two, Halo outshines InFAMOUS. Halo is still number one on Xbox live.
(Anyone with the misconseption that the Xbox had worse graphics then the PS3 is wrong, it's actually the other way around. The 360 had better GPU and other crap I can't really recall, and the PS3 makes up for it's weak GPU with some diversions here and there. Look it up if you want more proof.)
PS: DDX, IGN gave Halo a 9.5 while InFAMOUS got a 9.3 so not just one site can be truthful. As a matter of fact, IGN is known to get paied money underneath the table....I mean come on Ghost busters better then Prototype?)