We're making a whole new thread for this? I mean, the old one's been resurrected time & time again since, like, 2009, but ok.
Anyway, reposting the same ranking from that thread:
#1. Images & Words
#2. Six Degrees Of Inner Turbulence
#3. Black Clouds & Silver Linings
#4. Metropolis Pt. 2: Scenes From A Memory
#5. Systematic Chaos
#6. Train Of Thought
#7. Awake
#8. The Astonishing
#9. Octavarium
10. Dream Theater
11. A Dramatic Turn Of Events
12. When Dream & Day Unite
13. Falling Into Infinity