i will do the inevitable "staple band" and sub genre prog thread right now, so that noobs and people looking for some good starting points have something to get them going:
symphonic prog - Yes, Genesis, King Crimson, Camel, PFM
canterbury prog - Caravan, Hatfield And the North, Soft Machine, Egg
jazzy/jam prog - gilgamesh, national health, beggars opera, host
folk/acoustic/prog - fuschia, tudor lodge, spirogrya, comus, linda perhacs
psychadelia/prog - pink floyd, arzachel, donovan, locomotive, traffic
space/atmosphere prog - gong, magma, hawkwind, tangerine dream
krautrock prog - can, NEU!, birth control, pan, novalis, triumvirat
misc. prog - gracious, cressida, renaissance, van der graaf generator
scandanavian prog - bo hansson, flasket brinner, trettioariga kriget
worldwide prog - carmen, aquila, goblin, celeste, aphrodites child
classic rock/prog - uriah heep, led zeppelin, deep purple, black sabbath
new vintage/prog - landberk, anekdoten, wobbler, anglagard, dungen
prog metal - opeth, enslaved, arcturus, noekk, cynic, atheist
new era of prog - radiohead, the mars volta, porcupine tree, paatos