From Best to Least Best
Five Stars, 1. Dream Theater by Dream Theater
Five Stars, 2. Awake
Five Stars, 3. Octavarium
Five Stars, 4. Images and Words
Five Stars, 5. A Dramatic Turn of Events
Five Stars, 6. Systematic Chaos
Five Stars, 7. Metropolis Pt. 2: Scenes from a Memory
Five Stars, 8. Train of Thought
Five Stars, 9. Falling Into Infinity
Five Stars, 10. When Dream and Day Unite
Four Stars, 11. Black Clouds & Silver Linings
Four Stars, 12. Six Degrees of Inner Turbulence (I recommend the totally awesome 4 Degrees of Radio Edits, or Score instead)