Am playing very low limit NL and am wondering what everyone thinks is a good return. What sort of return are you all looking to reach before progressing to the next level? Is 20BB/100 hands acceptable or are you looking for better? At what number do you consider that you are good enough to step up to the next level?
Is there another measure that you use as a guide?

20BB is a very good win rate. If you can keep your win rate at 20 for a significant number of hands and have the proper bankroll for he next level, then you can safely move up.

I suggest at least 10,000 hands.