Darn, right at the last reply, now I look unoriginal. ;P
But yeah, Star Fox 2. The game was virtually finished (prototype ROMs are now available on the net, and people from CES recalled being able to beat it without issues), but Nintendo decided that it was too late in the SNES's life to profit, so they shifted focus on Star Fox 64, which was good, but "more of the same." Star Fox 2 had completely free-range battles, and shorter missions, but with more things going on (you had to keep an eye on Corneria to keep it from being too damaged by enemy attacks as you made your progress). It would've been very cool, and heck, still kind of is. Wish they'd do a GBA or DS port of Star Fox and include Star Fox 2 as a bonus.
People also swear by Treasure's Sin and Punishment for the N64, I've yet to play it myself because it was never released in the US (and I just haven't dug up the ROM).
TFLO and Four Horsemen are both interesting as well, and I'm glad both might still be potentially coming out, especially True Fantasy.