Start in Delaware- at Bethany, and go on south to Ocean City. You are also near the beaches in New Jersey. Bethany is quieter and more family oriented, Ocean City is busy and energetic. Ocean City has the best boardwalk.
We go to Delaware. Ocean City is too crowded and busy. We like Rehoboth and Bethany. Bethany is really nice, family oriented, clean and quiet. I've heard good things about the beaches near Annapolis also, but don't know personally.