I would get the Nintendo Wii then those two but from your list I would just get the XBOX 360 for the price. The PS3 will be worth buying, however I would just wait a few years until the price is much lower. The PS2 is really all you need at the moment. I have the PS2 and I will be getting the Nintendo Wii. It looks like the best console of the three.
It realy depends what games you like. Wii - mostly Mario and Zelda (and RED STEELE) Xbox - 360 - Halo 3 (4?) Gears of war PS3 - Metal gear solid 4 Killzone 2