The bootleg I've got of Orbital's Glastonbury 94 set takes some beating, and not only for sentimental reasons - it's just an amazingly exciting set, well constructed but totally fresh.
I love Kate Bush's performance of "Breathing" from ?first Comic Relief or Secret Policeman's Ball or something...all the overblown production is stripped away to just her urgent voice and the piano, and you can hear the true beautiful shape of the song. Sadly lost the tape I had of this some years ago, so any mp3s gratefully received!
The last session Nina Nastasia did for John Peel before his death is a treasured recording - it was when she was touring with two of the guys from Hun Huur Tu, and they did a load of new songs which rank among her very best. Also I saw her play on that tour and it was among the top live experiences I've had, so listening to that session brings back happy memories.