Where do you live and what stores which sell PS3s are in your area?
The latest PS3 slims on the Futrueshop (a Canadian store) are the 160 gig for $299 and they are still selling the 250gig for $349. There is also the 320 gig bundled only with the new Playstation Move for $399. (Prices listed in Canadian but I think they are similar in the states).
I have no idea if the move is worth getting yet or at all, and it isn't out until next week anyways. 160 gigs is plenty for a PS3 if you don't want to spend more than that. Your call if getting the extra 90gigs for $50 is worth it.
As for games, I highly recommend the following (off the top of my head, they are ones I have played)
Both Uncharted games, Rock Band 2 (or wait until RB3), Assassin's Creed II (it is a much better game than the first one, you can wiki the first games story if you don't intend to get it and suffer through the repetitiveness as it explains a few things in the 2nd one), The Beatles Rockband, Brutal Legend if you like rock/metal music, Dynasty Warriors 6 (and DW6 Empires) are surprisingly really fun for such shallow games, Infamous, Lost Planet 1 and 2, Saints Row 2 (I played it on the PC but it is a very good GTA style game, with a number of improvements over GTAIV such as vastly better car storage and its a goofy fun game),
Ones I haven't played but are highly recommended: the God of War games, Little Big Planet,