any world can be good (be oppertunistic, look for oppertunites and grab them as u see them). but i find worlds that are normally full to be best... (f2p ones to be specific, they seem to sell ores+bars more, and tend to be cheaper). my recomendation for worlds would be... 1, 3, 4, 5, 7, 8. or any another world with about 1,800 or more.... 1,900 or more is probably best... would 1 can get expensive and when it comes to selling members forum probably works the best (u can browse it as f2p). I suppose i should add that to the guide lol (have to remember to do that sometime).