I’ll go ahead and suggest you snag a used Gamecube, my video game store has a buy 2 used items get a 3rd free and you probably have the same store at your local mall, and then get Mario Sunshine and Zelda Windwaker. That’ll probably get you more fun gameplay cheaper then anything else. Just make sure you check everything out once you get home to make sure they work fine. Nintendo makes good hardware and I’ve never had problems with the used stuff I bought having bought a GC, DS and an N64.
The bonus of this is that it also gets you ready for the new Zelda coming next year.
Also Kingdom Hearts 2 is coming this December so you may want to catch the story so you can leap into the sequel since there will be threads on it here and you can participate. I wouldn’t play KH: Chain of Memories unless you really want to though.
Mario, Zelda, Sly, Jak and Kingdom Hearts, I say if you like one you should like them all. Plus they all seem to be moving in the same direction with only small variances. Although Jak and KH are the most cinematic and engrossing.
Harvest Moon!
I… I’m ashamed to admit, I do not know if you are a man or a woman. But you can get the game for either sex.
Most of this series is fun - it doesn’t seem like it would be, but you get sucked in. I don’t know if I’d recommend the Gamecube versions (they’re a little lacking, but I’m enjoying the For Girl version - the boy version kinda sorta blew). The most fun by far has to be the GBA version, Friends of Mineral Town (or, for girls, More Friends of Mineral Town). I’ve heard there was a version a few years back made for the PS that turned out to be a POS - the Nintendo versions are much more fun.
Just thought I’d mention it, your tastes are very, very similar to mine (except that I gave in to Evercrack (and now EQII). I’ve been playing for six years. I can’t stop. I still get out, though, and never lost a job because of it. 
)
I’ve been playing Pikmin 2, Nintendogs, busted out the old SNES to play Earthbound again (did you say you had a SNES? Maybe it was NES? I’m half asleep, here, pardon me).
I recommend investing sometime in a Gamecube, plus a Gameboy Player and a Wavebird. Play your gameboy games on the big screen with a good controller! From another room if you wanted to! (as if it made sense to, but I like to play from my sofa).
You’re not alone** Anastasaeon**. Alias loves Harvest Moon. Never played it, but is was on loan from a coworker and she wouldn’t let me near it. 
I’ll add my name to Ratchet and Clank. I just got Going Commando used and I love it. Good controls. Good gameplay. The sheepinator is loads of fun. The game is challenging without making you want to smash the controller.
Katamari is another good game. I think the original is $20 and the new one is around $30. I’ve never played a game like it. It’s a lot of fun.
I believe Resident Evil 4 is coming out for ps2 this holiday season. If it is, I’d put it down as a must buy. I never cared for any other RE game, but this game is probably my all time favorite. Good story. Great controls, Great graphics. It’s as close to perfect as games get.
If you’ve ever played Pokemon Snap, but wished it was a bit creepier, get Fatal Frame 2. The controls work perfectly. The graphics are spectaular. The story is top notch. Another close to perfect game.
The last game is Spider Man 2. The graphics are so-so in parts, and the story is good but the big money is in the controls. You can go all over the city pounding on thugs and the webswinging works perfectly. If you like Spider Man, or even just liked the movie, you’ll enjoy it. It’s also down to $20.
Moving thread from IMHO to Cafe Society.
If you like just stress relief, I’d suggest Hulk: Ultimate Destruction. You can smash, crush, and destroy anything you like, even without doing the story missions. it’s just so much fun, and you don’t have to pick up the comic to get it.
Another one with great replay value is Mario Kart Double Dash. Fun fun fun.
For console FPS games, I don’t think it gets any better than Timesplitters: Future Perfect. Unlike the previous two games, it actually has a decent story mode; and if you have PS2 online capability, the online play is free.
I’ll also heartily second Cave Story and both Katamari games.
Another one you can probably pick up cheap is Armed & Dangerous. It’s got a lot of shooting (too much for my taste), but it’s biggest feature is that it’s very funny. One of the weapons is a Land Shark Gun