Yes. Definitely buy it. I own PS2, GC, and a bunch of older systems. I got my GC for my 14th birthday (2004) and my PS2 just recently (September 2007).

I wasn't interested in PS3 as it is too much money and doesn't have a lot of games that interest me. PS2 has a wide variety of games and caters to everyone. I thought I would only get the KH series and maybe some DDR games but I ended up getting tons of games like Devil May Cry, Resident Evil, etc. Gamestop will be carrying PS2 games for many years to come as they still make new games for it. Plus you can always buy your PS2 resources on websites such as Amazon or Ebay.

Yes you do need a memory card.

lol.

I don't really have many PS1 games. Mostly fighters. Though my favorites out of the ones I do have would be

Street Fighter Alpha

Street Fighter Alpha 2

Tekken 1-3

Tomba

Beyond the Beyond

Rugrats (Gotta love it)

Bushido Blade 2

Streak

and a few more I can't think of at the moment.