In chronological order, the main ones worth mentioning are HopeRO, PlanetRO, CollisiaRO, QualityRO, LunarisRO, TenshiRO, VanRO, TsunamiRO.
Loved HopeRO just because it was where I grew up during childhood (metaphorically speaking in terms of RO growth). VanRO was one of my favorites despite the wipes every so often and the unbalancedness due to rich bastards and their donation money. I found I just really liked PK, so I can take all that anger out on random jackasses.
