I've got to say my music evolution is pretty linear. When I was younger I never did listen to much music, maybe a few local or Taiwan pop stars now and then, but its not even often I listen to them. Then I met the internet.
The internet really changed me as a person in the whole too, actually, but I won't go into that. The internet allowed me to listen to music from all over the world. In the beginning I only listened to some shitty stuff like Simple Plan, some stupid rap stuff and the occasional hard rock bands like Bon Jovi and Aerosmith. Then there was Rise Against, etc. It was more sparse and mainstream than what I listen to now. The frequency I listened to music increased, but it still wasn't a lot.
I was also started getting into anime back then, and that was when I started to fall in love with Japanese music, particularly J-Rock. I listened to L'Arc-en-Ciel extensively, and some other stuff like GLAY, Abingdon Boys School, T.M. Revolution etc. The generic mainstream J-Rock stuff of course.
I guess the J-Rock was what really got me into Rock and really guitar-based music, and I started to get more into Bon Jovi and Aerosmith and Daughtry and stuff, you know mainstream generic hard rock. Coincidentally, it was also around that time that I bought Guitar Hero, which introduced me to more music, and I fell in love with Black Label Society, Ozzy Osbourne, etc.
Long story short I got more into rock and all, and started to explore genres. I found The Who, Black Sabbath, Metallica, Nirvana, Beatles, Sex Pistols, Deep Purple Foo Fighters, etc. And most importantly I found Led Zeppelin, still one of my favourite bands today. And after listening to Black Sabbath, Metallica and stuff I got more into metal and listened to Iron Maiden, Judas Priest, Megadeth too. That was my 'old-music-is-better-than-everything-else-phase'.
Then some time later, for some reason, I tried listening to Muse and Radiohead. Best decision of my life. They were so fucking brilliant and I started exploring modern music again. I listened to a lot of alternative rock after that. Red Hot Chili Peppers, more Foo Fighters, QotSA, RATM, Coldplay, etc.
I tried exploring music even further after that, being a usual wikipedia surfer and seeing Muse classified into a 'new prog' genre, I decided to look into some of those bands. OH MY FUCKING GOD. Oceansize didn't particularly grow on me at that time, but they were pretty good to me, along with bands like Dredg and Amplifier which I listened to occasionally.
Then I decided to listen to more Prog, and I remember seeing a lot of good things about Dream Theater, I listened and I fell in love, then I listened to stuff like Rush and Porcupine Tree too. Its sad that Pink Floyd still seems seemingly bland to me today though.
After getting more into prog and alternative rock, I guess I went back to listen to more Oceansize, and it really really really grew on me. Frames seemed like the most amazing album ever (still is). I guess this was what really got me into prog and experimental music. Then I see stuff about Explosions in the Sky and I listened to them, beautiful! Then I also started listening to Post-Rock. When I got more into instrumentals, I also started listening to Shred guitar etc.
Then around this year, I tried listening to Death Metal seriously after putting it off for so long, and I realised my tastes grew enough for me to like it. It grew more and more on me, and I started listening to Opeth since it's one of [m]NeSchn[/m]'s favourite bands, and I have to say its worth it. I'm still more into Progressive and Technical Death Metal today than normal Death Metal though.
I still listen to a lot of Alternative Rock nowadays and I have to say, I'm completely rid of that 'old-music-is-better-than-everything-else' mentality now. The complexity you can find in modern music is mind blowing, modern music is full of polished gems with a lot of diverse musical influences and is much more complex than older music. It's like you can find 'Rush-level' bands easily today.
I have to say I have grown very deep into rock and metal music and I've been trying to get into Jazz lately due to listening to stuff like Atheist, but Progressive music is still my favourite. I think my tastes have changed and/or expanded a lot.