I have a G1 and a G2 and the 21mm lens. This is an unbeatable combination. The G2 is preferable, but the G1 with green sticker will work just fine in most circumstances. The Contax 21mm f2.8 is one of the best lenses ever made at that focal length - it's super sharp at all apertures, so much so that you can tell the difference between sharply focused and not sharply focused at f2.8 at infinity and near-infinity. That is a "you can pry it from my cold, dead hands" combo.