I've been playing the Budapest over the board and online for quite a while and I've always found the mainline 3. ...Ng4 4.Nf3 Bc5 5.e3 Nc6 to be very playable for black as you get active piece play and some attacking chances. It's important to get in a5 and Ra6 in this line. I've attached a recent game for you.Game 3792228
In the other lines black generally equalises althought the play is not as much fun. The key thing with the Budapest is that most players don't really know it too well so if you play with it a lot you can do quite well with it. I'd agree with some other posts though that it can be risky against high graded opponents.