I love fish. I love fish in just about every way you can love fish. (Well, not
that way
)
I love keeping aquarium fish, I love keeping pond fish, I love snorkeling and scuba diving with fish, I love fishing for fish, and I love eating fish. It's funny, though, that while my fish keeping obsession is strictly fresh/brackish, my diving/catching/eating is strictly saltwater (I have a house on Galveston Island). My favorite fish to catch and to eat are pompano, dolphin, ling, redfish, and trout.
I have already admitted my bias against freshwater fish, though I have had some good walleye and rainbow trout, but I do want to address my feelings about catfish and tilapia. I think most of their popularity with restaurants stems from their suitability for large scale aquaculture. I don't think either has a particularly great flavor or texture. Catfish I actually find unpleasant, but tilapia is not objectionable - actually, its pretty bland and nondescript. This is probably a big reason for its popularity (along with availability and price) with chain restaurants. Because it does not have any real flavor itself, it makes a good platform for any other flavors you wish to place on it. Look around, you're not going to find a lot of places serving simply grilled tilapia, it is always going to have some other flavor on it. But, that's okay, to each his own.
Oh, and shrimp, I love them. We're catching jumbos in the surf right now. And I've done very well catching blue crab and stone crab in the bay this season.