There are playable N64 emulators, but all of them are glitchy. Yes, roms are out there.
Here's a starting point:
http://spinal.emulation64.com/roms.htm It's a list of romsites, you'll find some dead links on some of the pages. I've got about 30 N64 roms by searching through a couple of the better sites, and I didn't download all the ones I could have.
As for an emulator, I'd recommend Nemu. There are quite a few N64 emulators popping up, but I haven't tried many of them. I've gotten the best results with Nemu so far. Get it at
http://www.zophar.net[ 26 May 2001: Message edited by: adidas ]