I'm more of a Merlot person myself. Covers the same territory as Brandy but leaves you able to wield the hammer and frying pan a bit longer.

We also use OraCompare a lot here. We're forever (or so it seems) comparing schemas between test and production servers verifying that our test environments are setup properly. Also came in very handy during a recent migration from Oracle 7.3 on UNIX all the way up to (don't laugh) Oracle 8.1.7 on Windows.

I've been told that Toad covers the same territory as OraCompare and then some.