I totally agree with Priest on the Turbo tour. That was a classic, Priest were bigger than ever and played to a sold out hall on Glenn Tipton's birthday when I saw them in 86.
Other concerts that come to mind - Metallica on the 93 Black Album tour, Maiden 10 years earlier (World Piece Tour), Diamond Dave's Skyscraper tour... Queensryche's Promised Land, Ozzy's Theatres of Madness.. Crue in 86...
Black Sabbath with Headless Cross was another awesome show, Ian Gillan joined in for Paranoid and Smoke on the Water and there were guys from Pretty Maids and Mercyful Fate in the audience and I remember running like maniacs to catch the last boat home .. god bless the Oresundsbron!
http://www.oresundsbron.com/Worst - there's been a few. Iron Maiden - I saw them twice in 88, one was great and the other totally sucked... Dio's Sacred Heart tour - fancy stage show but still not very good (Keel blew them away!!), Ozzy's Ozzmosis show - not much more than one hour on stage, Oz could barely sing and that guitarist...
The worst show I ever had the misfortune to see was however Backyard Babies/Drain STH/Clawfinger. I saw the Babies once before and they were great, I loved their album... they come out looking like wannabe punk rockers and play ONE song from their album and a lot of new, different and crappy material. Drain were quite OK, just never been a big favorite, and Clawfinger... they suck on record and they sucked even more live. What a bunch of no-talent posers... I think we left after three songs that were total garbage..