Since I had a $100 gift card from my birthday and saw EB's system upgrade special (1 old system + 10 games = $100 store credit), I went ahead and picked up a Gamecube even though I already have an Xbox.

I mainly bought it for Resident Evil (which is simply amazing), Rogue Squadron II (which I'll be grabbing soon), and Wrestlemania X8.

I've read a lot of the posts that mention Super Smash Brothers Melee and Super Monkey Ball as being great games, but I'm more of a sports guy and these seem kind of cartoon-ey to me. Am I missing something by skipping these? And are there any other must-have games out there that I might not have given a chance before?

I know this is a lame response, but your best bet may be to rent first. The reason I say this is because I loved Super Monkey Ball at first, but grew tired of it fairly quick. It's a good game, but not for everyone, yet others rave about it. On the other hand, I had no desire to play Super Smah Bros., but rented it one night when my video store was bare and I couldn't believe how addicted I was to it!
Since you said you like sports, I'd recommend All Star Baseball 2003. I stink at it (the opposing pitcher gets 18-20 K's per game against me), but it still manages to be fun.
I'm a Pac-Man junkie, so of course I love Pac Man World 2. If you're a Pac-Fan, well then it's a must. Otherwise, you may find it repetitive (lots of jumping) and short.

I've got ASB 2003 for Xbox and really love it. But the 162 game franchise mode is just killing me. I'm going for World Series Baseball after reading ign's franchise review. I've played something like 75+ games of ASB and the end is nowhere in sight after close to 2 months.

Super Smash Brothers: Melee seems to be the overall choice from my friends with Gamecubes as the best non-played purchase. I would rent some of these games if I could but my local video stores have 1 copy of each game and it's nearly impossible to get anything decent.

Since you like sports games, Madden and NBA 2K2 are great, but you might already have them for the X-box. NBA Street is awesome and isn't on the X-box.

Wave Race is fun while it lasts.

Super Smash Bros is a blast, especially multi player.

Eternal Darkness comes out in a month and a half and looks to be great.

Another vote Super Smash Bros.: Melee. I had never played smash bros. on n64 and didn't see what all the hype was about. I picked up ssb:m and started playing it for a while and I got TOTALLY addicted to it. It's really quite odd how that happened.

Smash Bros. is a must have. End of story.

If you want something different, try Luigi's Mansion or Pikmin. Both games are very original. They both suffer from the same short-coming though -- they're both relatively short games (maybe 10 hours each with limited replay value).

Since your a sports fan, you should really get NBA Street. The single player mode gets old somewhat quickly but the mutliplayer is a blast. I don't know whether or not you've played the PS2 version but the Cube version kicks the hell out of it.

Super Monkey Ball is an interesting decision. If the single player mode sounds interesting in the least, you'll probably like it because it's well executed. There's also 3 multiplayer modes (Monkey Racing, Battle, and Target) which are surprisingly fun despite being simple. There's also 3 mini-games (Monkey Golf, Bowling, and Pool) and these are lots of fun as well. To make the decision easier you might be able to find this game for $30 or maybe less.

Not to rain on everyone's parade but if you're not a fan of those games, steer clear. I picked up Super Smash Bros Melee. I brought it over to my friends with my Cube which I usually goto every other week to just play a bunch of shooters and sport games on the Xbox. We popped in Melee and the first thing out of mouths is "This is lame!" Then his 10 year boy and the neighbor's 10 year old wanted to show us how great the game really is. After the boys played for a while, my friend said then "I don't get it." I would have to agree with that statement. Maybe we didn't give it a chance but I just didn't see the excitement in the game. It is very cartoony for me and I will stick to my shooters and sports games. On Super Monkey Ball, you can find it for $30 new at a lot of stores and I think it was worth the price. The game is kind of challenging but I can see the novelty of it wearing off quick. If you're a sports genre game fan, doubt you'll enjoy either of these.

Slightly off topic... which systems will EB take for trade in? I guess I am wondering how old is old. Thanks

My opinions:

Super Monkey Ball is worth the $30 you can get it for. Lots of fun for single and multi-player, and quite the frustrating experience at times.

Rogue Leader: Might want to rent first, just because it is not a very long game. Fun, but if you are not a huge star wars fan, you might lose interest.

Super Smash Brothers Melee: Put me in the list of people who don't see what the big deal is. I really just demo'd this game at best buy, but it certainly didn't grab me. Seemed like just a cartoony, platform-based fighter. Might be fun playing with your friends, but I don't think it has much going for it in the single player department.

Just to respond the two who didn't like smash bros. melee. It seems like both of you only played the game for a short while. I totally understand how you feel. I didn't really "get it" for a while either. I kept on playing it and then I got really addicted to it. It's weird how all of a sudden the fun and addiction just set in. Just my opinion.

There's tons of things for a single player to do in Smash Bros. There are like a dozen different modes, tons of characters and levels to unlock, and all sorts of challenges to beat. I was thinking about trying to list all of the things you can do but it would just take to long I probably couldn't even the do the variety justice.

BTW, what does Smash Bros.'s "cartoony" graphics have to do with anything?

I traded in a Playstation 1 with 13 games, 8 of them had instructions and original case, 5 of them were disc only. I think I got 90 bucks out of the deal, or something like that. Some of the games were OLD like Madden '98, NHL '98, Apocalypse... I know the deal is valid for N64, PS1, and Dreamcast, I doubt it goes back farther than that but I'm not sure.

Doesn't really have to do with anything, except to give the person asking for recommendations some idea of what the games graphics look like. It is not meant as a slam, or anything. I happen to like cartoons. Just that most 3-d fighting games tend to have more realism-based graphics, so he might be expecting something different. Some people might find this a plus, other might find it a minus. Diff'rent Strokes.

I mentioned earlier in my post that I wasn't a big fan of "cartoony" graphics meaning only that I usually think of those kind of games as more kids oriented games. I know it's not true, I've played a lot of these in my day, but I'm much less willing to give them the chance to grow on me.

"I usually think of those kind of games as more kids oriented games. I know it's not true"

Problem solved. Go buy Smash Bros.