Gray Goose #3W
Ocean City has a ton of attractions, from minature golf to water slides, pizza joints to All-you-can-eat crab places to 5 star dining. There are plenty of water activities - jetski, parasail (Allie advises you go up 120 feet!), charter fishing, etc. There are playgrounds and parks (best probably at Northside Park on 125 - they have a pier for crabbing as well). A couple of movie theaters for the rainy days and outlets both at the Ocean City inlet as well as Rehobeth, DE. And of course you have the beach.
See HERE for more info or google Ocean City MD to see other activities.