I love shrimp every now and then, but I could eat a fried catfish with hot sauce every day!
Catfish (the one on the left) has a lot of fat, which I want to keep low for fish, but it looks great compared to shrimp in vitamins/minerals. I like to have a lot of variety, so as a single meal every now and then, both are nice. But, as a daily or every other day meal, catfish would have too much fat, imo. Shrimp as a staple would also not be great unless it was supplemented with vitamins.
Nice thing with both is some folks stick pellets in them, and some suggest injecting medications or vitamins in them.