My friend and I have been thinking about doing a video game marathon of sorts, but we're struggling to find a game/games to play. It's got to be fairly long, I'd say at least 15 hours, but more would be fine (I wouldn't say more than 30 hours though). It's got to be a game that we're familiar with, and it has to be on the N64, Gamecube or Wii. We've both agreed that it's not going to be a Pokémon game or a Mario game. We're currently thinking of a 100% run of Banjo Kazooie (All Jiggies and notes), but it's not ideal (we're both going to be playing at the same time on two games on two systems on two TVs, but he's got the N64 original and I've got the 360 port, which has a few differences).

SO...

Any suggestions?

Bad Fur Day and Live & Reloaded. Nah, uh....Goldeneye007 on N64 and Wii run through would make sense.

Metroid Prime series. All together they should be long enough.

I actually just did a run of Banjo Kazooie and, considering how long you want to be playing for, its not ideal. I beat the game in under five hours (then again I know the game like the back of my hand).

Majora's Mask could work, and you could play for story completion and mask completion, or you could just go with Ocarina of Time. So many options!

I agree with Zsaber. Actually, the Metroid series in general (except Metroid II, Fusion, and Other M. Too linear) would work for marathon running.

Unfortunately neither of us have played and Metroid games that much, and I don't own any of them, so the Metroid series is out of the question too.

SSBB for wii, or if you have the SSBM, even better. (I personaly like SSBM over SSBB)

Eh,....Resident Evil has had a lot of remakes from PS1 to GCN so you can possibly buy 1,2,and 3 and do a run on PS1 and gamecube. (I noticed you saying you having a PS1 in a thread)

Does Yoshi's Story count as a Mario game, per se? If not, I think ALL levels, ALL melons could work as a marathon game, although I don't really know who long it would take in reality.

How about Tales of Symphonia? It's long but I heard some gamers can beat it within 25 hours.

I'm thinking Subspace Emissary on SSBB. 100%. Not sure how long that would take but it'd be fun. If Mario and/or Pokemon games were allowed I'd say all the Star coin in NSMBWii, or play through Pokemon XD... But those aren't allowed, so SSBB is my recommendation. :3
Oh and if you don't have a certain game, like the Metroid games, you could rent them, you know.

If you can try a PS3 game. Sly Cooper Series is good.

Since Ocarina of Time is starting to get overused for marathons . I'd go with the Metroid Prime trilogy, though if you have ps2's, the entire kingdom hearts series would be so fun to speed run, in chronological order, or just KH and KH2. I can't think of much else.