I've got a party of 8th level PCs (7 of them) who absolutely demolished two fire giants (a CR 12 encounter) on Sunday. They used a combination of hold person and coup de grace to basically demolish one of the giants right off. Then they basically bludgeoned/hacked/wholloped the other one for two rounds until he died.
This was supposed to be a fairly epic battle, but it became anticlimactic in the extreme.
The party has magic items/equipment in line with their level (according to party wealth in the Pathfinder Core). Am I doing something wrong?