I've heard good things about the OK Joe's sandwich.
Tower Tavern on 31st/Oak has wonderful fish sliders on Friday's. Smaller, fried filet, cheese and a red pepper/tartar/aioli type of sauce.
Started out last year as a lent special, but they now serve them year-round
Funny turn of thread. I had a shrimp po' boy at Sol Cantina today that was much better than I expected, a very pleasant if squishy ciabatta, tomato and lettuce fresher than I would have thought, crunchy sweet shrimp and a nice sauce. No need to run out and get it, but if you're in the neighborhood, it's not a bad option.
More on topic, the friend I had lunch with said the Cure' of Ars shrimp dinner is this Friday, and he said it's usually a pretty good feast.