Belgarath, the GB G&W gallery games didn't do a lot for me, but they were pretty faithful.
What I did really love though, was the G&W Gallery Advance on the GBA -- it has tons of games in their original forms (very accurate), plus updated versions of them with nice graphics and some variations, and when you get high enough scores you unlock other games! Seemed to have a lot in it.
Even better IMHO is Wario Ware, Inc. on GBA. Closest you'll get to the spirit of those old games, except played at *light speed*. It funnels these little fun games at you every few seconds -- blink and you've got another game. Some folks hate it, I couldn't get enough of it.