Where should I go on vacation?

For my 21st birthday my dad said he would pay the fees for me to stay a few nights (with friends) at one of the resorts his timeshare includes. I would be traveling during spring break in March and only need to pay for my transportation costs. My trouble is that I'm broke right now, so I need the flight/train/transportation to be really cheap. Where is a good place to go on Vacation. I live and go to school in Boston and grew up in Vermont so I'd like to experience something other than New England unless someone can tell me somewhere cool that i havent seen yet. Where would you go? And why?