With the Wii being my first ever Nintendo console (although I have had Gameboys and now a DS) I'd like to take advantage of it's backwards compatability. I've picked up a wavebird controller already.

I've already decided to pick up Rogue Squadron and Resident Evil4, what are some other good single player games (any genre)?

no-brainer pick: Metroid Prime series (esp. the first one)

I would also recommend Zelda: Wind Waker though the sailing is a significant time sink

If you're into RPGs, Paper Mario. Racing, Mario Kart Double Dash. The Mario Party games are good with a group of friends, but I think the Wii has the party genre locked down.

*oops, just realized you wanted single player games. Scratch Mario Party off the list.

I'd also recommend:

Chibi-Robo (quirky little game - graphics are bland but the game is fun)
Star Wars Lego games
Eternal Darkness (IMO the best "adventure" type game on the Cube)
Viewtiful Joe
Super Smash Bros. Melee (some don't like it in single player mode but I logged a ton of playtime by myself)
Pikmin
Ikaruga (if you like twitch-shooters... but man this is a bruiser of a challenge)

Good choice with RE4,i actually just bought a Gamecube and that was the game i bought with it,amazing!

So now im also looking for good GC games once i finish this one.

Eternal Darkness
Metroid Prime (I wasn't a fan of the 2nd one)
Paper Mario: The Thousand Year Door
Super Mario Sunshine
Zelda: The Wind Waker
Star Wars:Rogue Leader (the 2nd one is ok as well)
Donkey Kong: Jungle Beat

And these are fun in single and multiplayer:

Mario Kart: DD
Super Smash Bros: Melee (tons of shit to unlock)
Donkey Konga

I was about to ask about Metroid 1 and 2. I see plenty of new copies of 2, not so many of 1. Which one is better? Also, how is Killer 7?

I greatly preferred the first 1. The whole dark world concept in the second one was annoying (too much standing around in the light to heal), and the bosses were overly difficult for me (but I hate hard games in general so that may not be an issue for you).

While I greatly prefer the first one as well, I did enjoy the second quite a bit. The dark world and needing light was actually fun for me and added a new challenge (and is not as much an issue later in the game).

A couple games that I loved, but seem to go unnoticed a lot, are Fire Emblem and Battalion Wars. I am looking forward to both the Wii vesions as well. Fie Emblem is just like its GBA counterparts (solid turn-based strategy) and Battalion Wars was just a simple, fun action game.

Killer 7 is whack - but REALLY worth checking out IMO. It's very unique, and will constantly having you say WTF?!?

Not to mention, it's sort of odd to hear a gamecube game yell out "Fuck you" everytime you kill something.

Eternal Darkness should be at the top of your buy list.
Resident Evil Remake is good as well if you've never played it.
Luigi's Masion is a fun little romp. Not terribly hard or long, but for the cheap price that shouldn't hold you back.
Pikmin 1 & 2 are excellent and bring a great new IP to Nintendo's stable of franchises.
Zelda: Wind Waker was great. A tad on the easy side as far as Zelda's go.

A few non-exclusives that would be good to pick up(if you haven't played), Prince of Persia: Sands of Time, Second Sight & Beyond Good & Evil.

Pikmin is incredible. It's fun, while puzzling and challenging, but also very relaxing. I never played two, but one is one of my favorite cube games. Probably top three.

Thanks for all the great suggestions. I mangaged to pick up RE4, and I so wish this control scheme is used from here on out on future RE games.

I'm going to try and track down Eternal Darkness and a few others that were recommended.

Eternal Darkness is a must. Probably the most engaging experience available on the Cube.

My list (some of the same as others)

Zelda: Wind Waker
Lego: Star Wars
Mario Paper Mario

and don't overlook Animal Crossing

Just echoing the others:

Celda: Wind Waker
Eternal Darkness (Which is overrated, but fairly decent.)
Viewtiful Joe
Metroid Prime (Awesome game, Echoes kind of sucked though)
Star Wars Rogue Leader: Rogue Squadron II
Super Monkey Ball (I love the single player in these games tho.)
Ikaruga (My favorite Dreamcast game... on the Gamecube)

Fire Emblem
Killer 7
P.N.03 (don't listen to the haters)
F-Zero GX
Tales of Symphonia
Baten Kaitos
Paper Mario
Donkey Kong Jungle Beat
Resident Evil 4

and the usual 1st party games.

Are Rogue Leader and Eternal Darkness OOP? I figured Rogue Leader would be one fo their value titles now.

geist was good.
surprisingly.
as was killer7.

Found new copies of Rogue Leader at Fry's. Went by Wal-Mart for something else and saw brand new copies of Eternal Darkness for $49!!!! Ouch....I have to ask...is it worth $49 5 years after it's release? I figured that it should be $20 by now.

It probably rings up cheaper than that.

I paid $50 when it came out. It was well worth it then, but you should definitely be able to find it somewhere for around $20.

Nope!! Rang up at $49.95!! Even the clerk who checked the price on it was surprised. He knew how old it was and figured it had to be cheaper.

Between just the 2 games I have already (RE4 and Rogue) I really underestimated the Gamecube and it's library of games.

Yeah there are some great titles. I was more impressed with the non-nintendo titles than what Nintendo offered. Like I posted above though, some were multi-console releases(BG&E, PoP, Second Sight) along with the RE's, Rogue Squadron II and Eternal Darkness.

I know that sounds odd, but I found most of the long running franchises paled in comparison to their N64 counterparts. Mario Kart: DD, Mario Sunshine, Celda, Mario Golf, Waverace, & Mario Party(s) to name a few. They just weren't as fun, IMO. So by this token I had given up by the time Mario Tennis came out, figured it would fall into the same category.

The stand out's for me were F-Zero GX, Pikmin, Luigi's Mansion & Metroid Prime(1). Three of which were either new or didn't have an N64 incarnation so they were naturally more fresh.

I didn't see Animal Crossing listed. I haven't played mine yet but a friend of mine was addicted to it.

I don't see it listed but I enjoyed Starfox Adventures.

Play almost liked a Zelda games. Bosses aren't that hard to beat except the last one, Andross was almost a pain for me but I beat him. I believe this was the last game that Rare Software made for Nintendo till they went with Microsoft. Not sure if is OOP but if you ever find a copy I highly recommend it for single player game.