PRIDE was awesome but sometimes it had so damn boring fights.
To me, the most boring fight ever is Kevin Randleman vs Michiyoshi Ohara.
Seriously it is a torture to watch the whole 20 minutes of that garbage. In the whole fight I think that only 3 or 4 punches landed.
If a fight like that happened today in the UFC, I think that everybody would leave the arena.
Fights that involved Nobuhiko Takada were also extremely boring (They were probably all fixed anyway).
Fights in recent memory....Kongo vs Shawn Jordan was really horrible. Leben vs Brunson, Nelson vs Mir.