alright, places i've been to and really like:
Fogo de chao - brazillian steak, all you can eat, 50 bucks a head for adults. really fancy and fantastic
http://www.fogodechao.com/index.php?id=164sabatino's in little italy - delicious italian, self explanatory. 20 dollar entree probably is average
http://www.sabatinos.com/also in little italy is Vaccaros - amazing pastry/ice cream dessert place. expect you and your wife to gain 5 lbs there because its that awesome
http://vaccarospastry.com/phillips seafood is a baltimore thing, but its a chain and clearly super exciting, but they have a new location now and i havent been since they moved
http://www.phillipsseafood.com/^^these are all in walking distance to/from the aquarium. if you are willing to drive, theres brewers art, which has great food and beer. they have a bar (dungeon style) or a formal dining room
http://www.thebrewersart.com/one place i haven't been to but my friends have told me about it is The Rusty Scupper. you can sit overlooking the harbor and they are supposed to have great crab cakes
http://www.selectrestaurants.com/rusty/if you want a chain type of place theres also bubba gump and mccormick seafood. both are ok but id go to one of the other places first.