I'm a pretty big Pink Floyd Fan.
Last night, a buddy and I saw "The Pink Floyd Experience" in Shippensburg PA.
http://www.thepinkfloydexperience.net/They were pretty good, but added some dramatic flair to most songs. The bass player and drummer were incredible. They have a sax player and seemed to add a sax solo to every song, which was a bit too much at times. They did a 7 minute capsule of "Echoes" that was neat. "Eugene", with a monstser bass solo was the highlight.
Last year we saw "Several Species", which is a huge ensemble band. They do the big production pieces, like from "The Wall" very well.
http://www.severalspecies.com/My favorite is "The Machine". A true four piece band that plays every Pink Floyd song flawlessly, including Echoes. They have a very cool laser light show as well.
http://www.themachinelive.com/All three go deep enough into the Pink Floyd to satisfy the most hard-core fans, but "The Machine" is my favorite.
