I actually picked other because I preferred the first Uncharted to the second, and I think it's the best game (series) on the PS3.
I agree with you, but I took another turn. I chose Uncharted 2 because I think the saga is the best PS3 exclusive out there, though Demon's Souls, Heavy Rain, Valkyria Chronicles and God of War III are also pretty good reasons to get Sony's console. Actually, all of them but Demon's Soul (with which I happily fell in love later) are the reasons I got my slim and I cannot recommend anybody hardly enough to do the same.
Killzone 2 is not a bad game at all but I think is not as remarkable as the others. Haven't tried MGS 4 out yet. I might do it someday.