I really like the way $okker does it. My other DD plays elite $occer and even the showcase tournaments do it this way. They are broken into pools of 4 and typically the top 2 in each pool move up into semi's. All games have meaning, so the teams work their hardest in every game. There are no throwing games to try to get a preferred team in elimination games. They even play this way at the best tournaments like STATE CUP where all the teams are strong and trying to acheive the state title.
Often times, teams can choose to play in Gold or Sliver play kind of like entering A or B divisions in tourneys. It helps keep the talent kind of clustered together. Sometimes you have the trophy hunters in the Silver division, but it does not happen often since it is no fun.
The best part is that there are NO GATE FEES at $okker tournaments!
I have seen softball tournaments in Toledo use a similar format at the Fastpich Classics series run by Mark Tooman. It seems to work well.
Fastpitch Classics
I think that they also did something similar at the Farley Memorial tournament (ASA FAST Wizards) this year where only the top seed in each pool moved on.