My worst gig was early 80s, Sugar Minott at The Centre, Slough. Not only did he not turn up, neither did the support band. Still, only three quid on the door for a dub reggae disco in a venue full of ganja smoke. I'm surprised I remember it...
Worst I ever saw was Hawkwind at the Sundown, Mile End Road. It was at the height of their 'Silver Machine' chart success in 1973, their sound system was totally f*cked, they were arguing with their roadies and there ended up with punch-ups in the crowd. The music, if that's what you could call it was sh*t that night. To top the whole thing off Statia, their statuesque and well-formed dancer didn't get her kit off! It also didn't help that they had The Pretty Things opening for them and they were brilliant...
I think the first one was The Groundhogs at Kingham Hall in Watford, 1970 I think. Saw Led Zeppelin at the Bath Festival (1971) - incredible even at that early time. Other memories were Humble Pie at Buxton and the Allman Brothers Band at Knebworth.
I was there! The Medics had a solid following then came Spirit in the Sky and it went mental. Probably the best era for me and my mates who were at gigs every week around London. Hammersmith Palais was superb, such a shame it stopped doing live shows, lots of flats there now.
Iggy pop supported by the slits and aswad 1978 I think at the venue Victoria and guess who was playing keyboards for iggy, one David Bowie - brilliant my second all time fav gig ( the clash 1982 at the Lyceum, if you are interested)