Cruise's performance in The Firm was OK. The problem was that the movie was a big re-write of the book, but I can't fault Cruise for that one.
Only Cruise movie I liked was A Few Good Men. It was obvious from the film that Cruise had altered his approach to come across more like a Mark Harmon-ish character. (And given that Harmon is a MUCH better actor, that wasn't a bad thing)