I STRONGLY suggest that if you haven't yet, everyone check out Ayreon's album "The Human Equation". something there for everyone. hands down, my favorite concept album of all time. a couple choice tracks to check out:
Ayreon - Day Eleven (Love)
http://youtube.com/watch?v=YTSt58Xelz8
Ayreon - Day Sixteen (Loser)
http://youtube.com/watch?v=qtAhlPcdh9c
Arjen Lucassen explains the concept + some outtakes
http://www.youtube.com/watch?v=JSnTYFtlkzM&NR