I'm being a little liberal about Big 5-10, but tried to pick some of the larger groups.
Still play frequently:
King Crimson
Pink Floyd
Gentle Giant
Camel
Still play on occasion:
Yes
Rush
VdGG
PFM
Banco
Magma
Soft Machine
Rare or never:
ELP
Genesis
Jethro Tull
Zappa
Bookmarks