Wow, is what I have to say about this album. Epica seriously brings the 'Epic' this time around. On top of the great single Unchain Utopia, the entire second half of the albums stands out as well as track 2, The Second Stone. I think Omen takes the cake as my top track though - just seriously fucking epic. One of the best, if not the best, symphonic metal albums I've heard.
Epica charge their music up on The Quantum Enigma with results that are both surprising and striking. The album makes one hell of a first impression and though the flair does wear off after a few listens, it remains an easy album to return to in small bursts.
This is probably the best that Epica have ever done. It's heavy, catchy and contains some of the best song writing of their career... of course it's still Epica, so there's the big 'cheese' factor as well.