You know what I like? Louis Kemps Crab & Lobster Delights. They are a little pricey, but worth it for a non-fish eater. You can have the whole 8 oz package to yourself & it counts as a 4 oz meat serving, I think.
I like to heat up the 'lobster' in the microwave a little bit & have it with butter spray, or a small amount of real butter. You can put this over pasta, rice, a baked potato, or eat it just like that.
The Crab Delights, I like to throw into a pasta salad, made with a bit of light ranch dressing, whole wheat corkscrews, frozen peas that have been thawed, small bits of carrot & onion, then seasoned w/black pepper. But they can also go on top of pasta, rice, baked potato, etc.
You can also throw either in a lowfat tortilla w/some lowfat cheese & salsa & have a taco.
If you're going to eat tuna, make sure it's not too often & not albacore, there's been news lately about dangerous mercury levels? Chunk light tuna is allegedly ok. I like it mixed with the new Light Wasabi Mayo.
I like to 'frost' a salmon fillet with Miracle Whip Light, then sprinkle w/Mrs Dash's, then bake according to package instructions. The Miracle Whip keeps the fish moist & tangy. You can also get canned samon w/o the skin & bones. I like to mix that with plain nonfat yogurt & dill & a little onion & just a squeeze of lemon juice.
I like shrimps, too, one of my favorite dinners ever is shrimp cocktail. You can also get Light Parmesan Alfredo by Ragu--lighten it up a little further& thin it out to the consistency you like w/some skim milk & make your own shrimp alfredo.
As far as fillet fish goes, you really can't go wrong grilling it or baking it w/some lemon butter & grilled vegetables, as a general rule of thumb.
Good luck, let us know how it goes!!