Watching too much anime can cause JPop/Rock/Hiphop addiction.
It all starts out quite innocently. You hear the anime's opening theme and don't think much about it because you don't understand Japanese. Then you start noticing how awesome the video sequence that goes with the opening theme is. Then you realize that the music is a perfect fit for the anime you're watching. Pretty soon you hear the darn song in your head every time you see the anime's main character. Then you just have to look it up in YouTube because you're curious to see the artists behind it. And then you find the video to the full version of the song and that's when you're hooked.
Well, that's how I got hooked anyway. :D You know... why don't you try it? You might like it. ;P I'll even point you in the right direction. Here are a few of my favorite anime opening/ending themes right now: (By the way, don't mind the incomprehensible English lyrics, a lot of them are incorrect. Hehe.)
Abingdon Boys School
Darker Than Black Opening Theme 1
The World Without Logos
Hellsing Opening Theme 1
Code Geass Ending Theme 2
Great Teacher Onizuka Opening Theme 1
Bleach Opening Theme 1
Shiki No Uta
Samurai Champloo Ending Theme
GetBackers Ending Theme 4
Now go look for the full version original artist videos of these songs on YouTube and you'll be a bona fide certified JPop/Rock/Hiphop addict. :P