I don't like Dream Theater as much as I used to and consider them more of a guilty pleasure than anything, but I still think Images & Words is absolutely brilliant. Most of the criticisms people love throwing at Dream Theater don't apply to that album or at least not to as large an extent as to the others. It's not prog for prog's sake, it's what prog should be, it's inspired, mindblowing, brain-tickling music that could only exist in time signatures no sane man would touch.
The only problem I have with that album is that while all the individual songs are great, the album as a whole is very incoherent. Were they going for intentional contrast when they placed Another Day after Pull Me Under? Whatever the case, it doesn't work and it's jarring as hell. The rest of the album isn't much better in that regard.