Well, back in the day I didn't know about ROMs, so I was happy with actually owning the games. Considering emulation isn't perfect for even some SNES games (try playing Stunt Race FX sometime), having the real thing is preferable. Getting N64 ROMs to work right is much harder. To date "World Driver Championship" is still unplayable as a ROM, unless you download some special hack of a graphics plugin for Project64, and even then I heard the framerates are horrible. I tried playing the game anyway and my computer just couldn't take it. Too bad, that was one of my favorite games for the N64, even if it was the longest 40 hours playtime of my life (you start to get tired of the Sydney course after the 10th time through). I'm not even going to try GameCube ROMs, my computer would probably blow up (or catch a virus, whichever comes first).
But ROMs are how I discovered Secret of Mana and Banjo-Kazooie. I later bought Secret of Mana off the Virtual Console because it's much more fun to play with an actual controller. Well, except for the GameCube controller which just seems bulky.