Rusty Scupper in Baltimore has some good Happy Hour deals. HH is from 4 to 7 weekdays. They have a couple beers for under $2 (usual price is over $5!).
There is a happy hour menu that includes crab soup, calamari, popcorn shrimp, hamburger and french fries,caeser salad, and crab and avacado dip. I've had a few of these and they were quite good. All of them are $2 each and the servings are generous. They give you a surprisingly large plate of calamari.
My only complaint would be the french fries that come with the hamburger, but the hamburger is well worth your 2 bucks.
They also have a great view.
If you go, look for the cheap parking on Covington St. next to the Visionary Art Museum. The brown meters give you an hour and 15 minutes for a quarter.