well, it depends... if you wanna go into the old school shit, the best was Flicker... on habbo it made you flicker, on coke, it made you invisible, serverside... that, or walk through furniture...
Best filter would be fake becuz it owns noobs who dont know about fake furni
Actually it's the worst because newbs have gotten ahold of it and now people who aren't newbs are getting pretty pissed. I would say the best filter is Buy Sharktale.
I'd say the best filter would be either the teleport filter, or the filter that let you buy ANY rares out of the cataluge, including pins, bass fishies, gold and plat records, etc. But those filters have been patched for a long time.