It's really hard to compare all the albums cause they all are very different from each other and have their own strenghts. I still think "V" is a tiny bit ahead of "The Odyssey", "TiO", "TDWOT" and "The Damnation Game". I just think the concept as a whole is absolutely perfect. Maybe it's not really the better music on "V", but the whole concept just makes this album very special imo. Everytime I listen to that album I'm fascinated how flawless it is. Every single song adds to the atmosphere of the concept, and that's really a rare thing looking at all these "wannabe-concept albums" out there.
On the other albums there are really great moments as well (the song "The Odyssey" is easily on the same level as "V" imo), but there are also songs that dont move me that much. I couldnt name a single Sy-X song I dont like, but there are some I like more than others, and on every other album there are one or two I like a little less than the others. On "V" I cant really name a favorite or a least-liked song, they are all just equal - equal on a VERY high level that is.