This is a shameless rip of the same thread that I made on another forum. Deal with it.

Anyway, Dream Theater is a Progressive Metal group that was formerly known as Majesty. The members are Mike Portnoy (Drummer, fucking badass one at that.),
John Petrucci(Top 5 guitarists in the world.),
Jame LaBrie (Vocals.),
John Myung (Bassist),
and Jordan Rudess (Keyboard, badass at that.).
Albums include:
When Dream and Day Unite ( 1988–1990 )
Images and Words ( 1991–1993 )
Awake ( 1994 )
A Change of Seasons and Falling into Infinity ( 1995–1998 )
Scenes from a Memory and first live DVD ( 1999–2001 )
Six Degrees of Inner Turbulence ( 2002 )
Train of Thought ( 2003–2004 )
Octavarium and Score ( 2005–2006 )
Systematic Chaos ( 2007 )
BC&SL ( 2009 ) #6 on the Billboard 200!

My favorite as of right now is BC&SL, followed by Six Degrees.

Ahh yes... Dream Theater... They're alright. Some of their music just make me go insane. But thats ok.