Star fox is good, but you'll beat it in maybe 4 hours or less....Kart DS is cool, I've played all of them and it's still good. It's also pretty cool just because you're so used to playing on the TV and having to stay stationary, but now it's portable and you can play it anywhere...almost a little creepy...a good creepy.
I've read up on Advance Wars, it seems like a long game and it looks pretty cool. I'm sad to say that I've nvr played Castlevania, but I guess it would be an awesome game.
Diddy Kong would give you pleasure for the whole trip I would guess, it looks great, but not exactly like the original. Metroid has nvr been my thing, but I got it for Christmas and it's ok.
Animal crossing sucks like a baby on a pacifier if you've played the gc version already, but if you haven't I suppose it would be a good experience for you.
There's a ton more games, so go look up reviews on the net for yourself!