Overrated seafood: halibut. chicken breast of the sea, and I'm sorta saying it's as bad as chicken, so nuff said.
Underrated seafood: skate liver. way better than monkfish liver
Overrated meat: close call between tenderloin and the eye or loin part of rib eye which tastes pretty much the same as new york strip which also is boring as hell. I wish, someday, they'll sell the cap and the eye of rib eye separate. They really are two different muscles that need to be cooked separately.
Underrated meat: goat heart. Probably the best heart I've ever had. Better than beef, pork, chicken, lamb, and venison, and everything else...
Overrated veggie: veggies are all overrated :) I, as a man, hunt, kill, and eat MEAT!