I was going to mention both Haddock, and Pollack. Other good choices include red snapper, whitefish or walleye (Great Lakes fish), Jumbo Perch, small mouth bass, and Boston Blue Fish. If you want more flavor, but still fairly mild, fresh pink salmon is amazing, as are speckled trout fillets, or swordfish. Yellow fin tuna, if it's fresh is also good. Catfish, if caught in clean water, is mild and has the proper texture as well. Herring will work.
These fish will work, but will need to have the fatty parts removed:
Chinook Salmon, Lake Trout, Pike (can be very bony if not prepared right), sockey salmon, coho salmon, steelhead/rainbow trout, most tuna.
I've had battered pink salmon that had no fishy flavor, and was an absolute delight. I've also had salmon where the fatty meat from under the dorsal fin, and belly meat was left on. It was not good eating. Fish fat is very strong flavored, and isn't tasty to most people. Think cond-liver-oil flavor. Remove the fat, and sometimes the skin, and that same fish can be wonderful.
Seeeeeeya; Chief Longwind of the North
