Solos eh? Well, there are obviously hundreds of them, so I'll just name a few that pop into my head...
Andy LaRocque of King Diamond is one of my favourites. A prime example is his lead work on Invisible Guests on "Them" or that beautiful arpeggio-based solo at the end of A Visit from the Dead from Conspiracy. Dressed in White as well... I should also mention his stuff on Jealousy from Individual Thought Patterns (Death) and Trapped in a Corner, same album.
Kai Hansen's stuff on I'm Alive, Halloween, March of Time as good examples... Lust for Life solo from Heading for Tomorrow (Gamma Ray)...
Criss Oliva, a god among guitarists, his best work imo can be found on Edge of Thorns...
Hangar 18 and Tornado of Souls are ridiculously awesome as well (Friedman)
Saw some Kreator mentioned, so I have to throw in the solo in When Death Takes its Dominion (from Enemy of God). I used to listen to that beauty over and over again...
Joey Taffola may have just put down his lead stuff on Jag Panzer in a manner of hours but he still managed to write fantastic solos in TheFourth Judgement album. I'd single out Black, Shadow Thief and The Fourth Judgement.
Toxik! Josh Christian was the man, World Circus solo, Think This, Heart Attack...
Flotsam and Jetsam, I Live, You Die, great leads, especially the part where they double the vocals of Eric AK in the middle section...
Dream Theater - Under a Glass Moon, still Petrucci's finest moment imo...
Carolina IV double lead, by Angra off Holy Land...
Back to work...