There are a half-dozen or so Zimmer scores I think are outstanding but which no-one ever seems to talk about. At the top of the list for me would be THE HOUSE OF THE SPIRITS, BEYOND RANGOON, A LEAGUE OF THEIR OWN, and COOL RUNNINGS.
I'm not a big Zimmer fan (much more into traditional, orchestral, theme based scores), but there are some of his scores I like a lot. Besides his usually praised scores for Inception and Pirates Of The Caribbean At World's End, some other Zimmer scores I like are:
Hannibal is wonderfull and not oftenly praised. It is probably my favourite score from him, even with the dialogue at the album.
Mission: Impossible 2 is a score I like a lot (not much his take on the theme, but the rest of the score). I never understood the negative reviews on this one.
Definitely BEYOND RANGOON -- my favourite score of his, without question.
Oh yes. An echo of this sentiment...Beyond Rangoon is my favorite Zimmer score without question too, and I also think it is vastly underrated.
Also The Pledge, a score unlike any other in Zimmer's career. Yes, it was co-composed by Klaus Badelt and I don't know how much score/ideas/execution was Zimmer but as it has his name on it I rank it up there as one of my favorite Zimmer scores and along with Beyond Rangoon also one of his most underrated.
For me, it's a tie between THE FAN and HANNIBAL. The former never got a proper score release and the latter was marred by dialogue, so they can't be judged by their OSTs alone. And, despite Zimmer's utter hatred for the film it was written for, The Fan is quite melodic and would make a great 55 min CD. Again, they're not the best Zimmer scores, but neither are mentioned with any frequency and both are fun listens.
