PokerRoom host the excellent "Royal" poker tournament which is a $15,000 guaranteed prize fund, freezeout tournament with a buy in of only $10+1
PokerStars host the incredible "Sunday Million" online poker tournament which currently has a $1,500,000 ( yes, one and a half million dollars! ) prize, with a buy in of only $215
Unlike rebuy tournaments, with freezeout tournaments, if you lose all your chips, you are out of the tournament. This means that freezeout tournaments provides a more level playing field, as those with large bankrolls cannot simply buy their way back in. The main event at the WSOP is a freezeout tournament, not a rebuy.