The season for cheap packages to London is upon us, and Gate 1 Travel, by way of Travelzoo has a great deal to London. This winter $299 gets you a flight from NYC and 4 nights at some random hotel in Bayswater. That’s a great price, but possibly even better is that add ons from other cities are extremely reasonable (Chicago’s just an extra $90, for example).
If you’re just looking for a cheap flight to Cancun, Spirit Airlines has $198 round trips from New York to the spring break mecca. Of course, it’s not during spring break, but I’m sure you’ll find something to do there.