12-3/12-5 if you want higher level manyu/better exp without including SG runs/to collect ampis while you're farming.
Run event maps if you want to get a mix of exp, gold, ampis and Life Gems/want to get the bonuses offered from the event past 4E/5S Rainlily.
2-1 if you want more numerous lower level (5-20) manyu/better exp including SG runs/can't effectively run 12-3 without needing helpers/can't afford the 80 stam SGs.

Really what you'll run depends on what you're looking for at the moment.