My tastes have always been pretty eclectic. As a young kid I was exposed to everything from The Beatles to Willie Nelson through my parents and their friends, so I'd always heard a wide variety of music. Up until I was about 8, I mostly listened to Elvis Presley and The Monkees. In fact, I had a serious obsession with The Monkees and to this day far prefer them to The Beatles.
Thanks to my parents, I heard a lot of The Beatles and The Who; I always enjoyed The Who and still do to this day, but I grew sick of The Beatles fairly early on and never really liked them much since.
Despite my reputation as "The 80s Guy", I was too young to fully appreciate all the stuff from that era until the early 1990s. I was aware of and had an appreciation for what was popular back then, and thanks to my older sister I was always exposed to a heavy dose of MTV, but I didn't fully branch out until around 1990.
When "Wayne's World" came out, I heard Queen for the first time and "Bohemian Rhapsody" completely blew my mind. We had just gotten a new stereo, so I went out and got a few Queen CDs, the first CDs I'd ever owned. By age ten I was listening to a ton of rock music from the late-70s through the early-90s, heavily favoring bands like Metallica, Guns N Roses, and a lot of the hair metal stuff. I never really distinguished between styles, to me if it had drums and guitars it was "rock", whether it was hair metal or thrash metal or whatever, I enjoyed it. At first I really hated rap, but I eventually warmed up to some of it. It's still not a favorite genre of mine, but there's stuff I enjoy, which would have been unthinkable when I was 10.
Nirvana became my favorite of everything when "Nevermind" came out. It seemed to so perfectly match my pre-teen angst.
When Offspring and Green Day broke big around '94, I started listening to a lot more punk-style music, which I still enjoy. People can knock on those two bands for not being "real punk", and I wouldn't argue, but if many kids did the same as me - get hooked on Offspring, then go back and get hooked on The Ramones, Black Flag, Bad Religion, Pennywise, etc. - then I say Great Job to them. Then, when I got to high school, there was a huge kind of cult thing going on where a lot of kids started re-connecting with all the 80s bands that were no longer "hip" to like, and that's where I fully formed an appreciation for GNR, Poison, Motley Crue, Van Halen, etc. The upbeat, semi-cheesy, over-produced style seemed a perfect counter-balance to all the cynical, jaded, "college rock" that was en vogue in the mid/late '90s - a lot of which I also liked, but still, a little balance is good. Freshman year, I was also introduced to The Misfits, which became and remains a huge obsession. A lot of what I got into that year, I credit to a bunch of Senior kids I was friends with, who would almost exclusively listen only to stuff from the 80s.
So now, compared to when I was a kid, the stuff I like the most still remains GNR, Metallica, Offspring, AFI, Bad Religion, Nirvana, Bon Jovi, Kiss, and Queen. Occasionally I'll listen to some N.W.A., or KMFDM - oddly, "Juke Joint Jezebel" may just be my favorite song ever, for some reason - and I don't mind country music much. The only stuff I can't stand is the Grateful Dead and stuff like that, although I do like some Spin Doctors and Soup Dragons stuff, which is kind of similar, I'unno. I also like a lot of the "Nu-Metal" stuff like Drowning Pool that was so big in 2002 and so hip to hate nowadays, but objectively, it's mostly just good for working out to.