Only 5?????

Off the top of my head it would be (in no particular order):

1) Yes - Magnification.
2) Moody Blues - Strange Times.
3) World Turtle - Wilderness of Eden.
4) Ozric Tentacles - Live Underslunky.
5) Pink Floyd - Echoes.

I know the last one's a bit of a cheat as it's a compilation but I love it!!!!!!!!!!!!!!!!!!!