Some people say 15xBB is enough for SNGs, some people say 20xBB, others say 25xBB, there are some that say 30 or above should be the minumum for a serious player at the high levels.

I have gone many many OOTM before, and i can guarantee that 15xBB is not enough, especially at Party poker. There have been variance simulations where a realy good player can go through 17 Buyin drops. I think the minumum should be at 25. But thats just me.