Looks like Ocarina of Time is the most requested remake looking at the replies. And some want Mario Galaxy as well. Overall most want Zelda or Mario.
OOT is the most requested game, but GameCube games are the most requested overall, and I'm going to add to that.
I want HD-uprezzed re-releases of both Baten Kaitos games. Any good game released on GCN that doesn't have Mario, Zelda, Pokemon or Metroid in the name deserves a second shot at finding a real audience, and I'm always going to shill for them because unlike SM64, SMG 1 $ 2, Ocarina and Majora, they have never been re-released in any form. There is no decent way to acquire these games outside of emulation or paying a pretty penny for GCN copies.
FREE THOSE GAMECUBE GAMES NINTENDO!