I had a mid-winter there to the Bansko ski resort which was loads of fun. I also had a a day and night in the capital Sofia, and have to say that Bulgarians really are incrediby friendly - I know that's a cliche but everyone seemed dead helpful and nice.
The chicks in Sofia's premier nightclub, Yalta, were stunning too

Yalta was a pretty good club actually, David Morales was headlining the night I was there. Good set too.