Brussels Airlines has a special offer for tickets between April and September to a whole range of European destinations, plus Marrakech and Agadir.
Tickets start at EUR 59 all included, roundtrip (yes, really!) for the cheapest destinations, but availability is quite limited. I looked at a dozen destinations and the website’s search engine only gave me dates in the 2nd and 3rd week of June. Of course, if you can travel on weekdays, your chances of finding a good deal are higher.
Last day to book online: 9 February 2011.