Whoa, Uncharted 2 is what u are recommending he get? Back up.
Metal Gear Solid 4 is the best game ever created, and it is only on ps3. Definitely get that. If you're only getting one more game after that, I'd say get a shooter so MW2 or Killzone 2.
How I rank exlcusive games on ps3:
1. MGS4
2. Killzone 2
3. Resistance 2
4. Motorstorm 2
5. Resistance 1
6. Infamous
Then it goes on with stuff like Motorstorm 1 and crap that would be pointless to get. If you like racing, just get #2.
I never played Uncharted, but I would probably throw #2 right in after Resistance 2. Wouldn't it be better to play the first one first anyway since its like a story game, not a standard shooter or racing game or some crap?
Multiplatform games to consider:
Devil May Cry 4
MW2
Borderlands
Oblivion + Fallout 3 (I don't like these games, but most people seem to)
Soul Calibur 4
Bioshock and in the future Bioshock 2 (I'm not a fan of this one either, but people like it)