We don't have a lot of restaurants that specialize in seafood, and I agree with your assessment of Catch 35 and Nick's.

Beyond these, there's L20 and other fancy places, the steakhouses, Frontera for ceviche, Greektown, and some chains (Roy's, McCormick & Schmicks).

I had great oysters and ceviche at Amelia's Grill, but that's in the middle of nowhere.