Metal Gear Ac!d, for those who want something different- and can get over their stigmas about card gaming. I know I have. Oh, sweet merciful MG Ray card costing 50,000 points, you will soon be mine...
As far as games that are sold out, first and foremost, it's Ridge Racers. From Secaucus NJ to Manhattan NY, anyway. Unconfirmed but logical reports have been saying they underprinted copies of it... I stopped in at a shop in Brooklyn, they had three copies, but when the guy pulled it out of a garbage bag (albiet in pristine, wrapped condition) and asked 45 for it, I got a little wary... when I offered 32, and he went in back to "talk to his boss", I took that moment to tuck my PSP case clipped to my belt and jam it in my pocket. He said I could give the 32 and just come back to pay the rest tomorrow... but I'm guessing he meant leave my 32 there with the game, which wasn't going to float in my book.
MG Ac!d is definitely next on the unattainable, but can be found from time to time.
As for a third game, well, I'll leave that to what you like- puzzles, sports, Apes...
I just want my Ridge Racer, damnit. (But I love my Ac!d... Hell, I bought the PSP for that reason alone.)