Never fear... Hairbndrckr is here to sort this mess out for ya...

First of G-n-R were the kings of SLEAZE metal, not hair metal
Sleaze metal came about basically because G-n-R didn't fit into the hair scheme. Other bands in the Sleaze metal genre were:
LA Guns
Faster Pussycat
Shotgun Messiah
(you get the picture)

Hair Metal was just that. It was an Aquanet revolution. The higher the hair and more makeup you wore, the better the chance you had of getting laid. Also if you were in a band and you ever wanted a chance in hell of getting signed, the power ballad was a MUST HAVE in the arsenal... You can all thank Motley Crue for that one... I know, there was more than one time I felt like choking the $hit out of those boys for doing that $hit, but it did get you laid...

For those of you who were talking about Megadeth, and Metallica$h, back in the days they were know as THRASH metal bands and were thrown into the mix with the likes of:
Overkill
Anthrax
Merciful Fate
King Diamond
etc.

Also there was also the hard rock brand being thrown around. Bands that were considered hard rock at the time were:
Van Halen
David Lee Roth
Sammy Hagar (pre halen days)
Tesla

There was one more, but people tend to not admit it. There truthfully was only one band in it. That was the whiny puss-metal genre, and that band was:

Slaughter

Ok class... any questions? No? Good...
Class dis-MISSED.