I think you posted this in the wrong area, wouldn't this be general Android apps? This isn't specific to the G2.
That being said, I'll still answer the question.
I don't know about 'light' emulators, per se, but you do find different qualities of apps. Mainly because some are mere ports and some are good, ARM-based apps. "Legend of Zelda" doesn't tell me what system you want to run...
If you visit the Coolrom page on your phone for the version of Zelda you want, the recommended emulator that they post for whatever system you're looking at is good. Off the top of my head, that'd be:
-DraStic (DS Emulator)
-Super N64 (Nintendo 64)