Being a fan of Linkin Park, I thought this album was great. Disk 1 is the album hybrid theory (I won't repeat what the other reviewers have already said). I would rate this part only 3 stars, I prefer LP's Meteora.
However, listening to Disk 2, which includes 'High Voltage' and 'My december', made me change my mind. These songs are actually taken from Linkin Park's orginal album, Hybrid Theory EP (which not many people know about). Unfortuately, H.T EP is very hard to get hold of now unless you're willing to pay very large amounts of money for it, so this is the next best thing.