Hybrid Theory is just exceptionally AWESOME; however, Reanimation is cool, too.
They are both awesome in their own ways imo. I'd say I like Hybrid Theory, just because of how revolutionary it was. But when I got hooked on LP, it was the only rock band I knew at the time, so by the time I listened to all three of their albums (this was in 2009) for a long time, I started running out of new stuff, so Reanimation was awesome cause it kept me going with new stuff until I found other rock bands. I guess that could be why it's awesome. And also it's a really unique album, and it's a bit more than just a remix, it's almost like magic (of course all of LP's music is like that ;)). Both are really cool, and I couldn't imagine my life without them. My favorite tracks off of each of them are crawling (I'm a big crawling fan lol).
BTW interesting thing I found out the other day - Reanimation is the highest selling remix album by a rock band, and the sixth highest selling remix album period. How cool is that?