All down to one's preferences of the day (for me at least). I remember a thread a little while back asking for one's fave prog albums starting from 1969 up till the present day. I think I made three different ones and still felt like I'd left out a big chunk of my favourites. 

Still this is a luxury problem. I can never understand people who have their faves set in stone. I could never do that, because my tastes shift from day to day. Don't get me wrong, it's not like I adore a certain record one day and then the other want to throw it out the window..........but I may be more into RPI and Fusion on a Tuesday while infinitely more taken aback by Krautrock and RIO the following Wednesday. 

BTW John. Have you checked out Syd Arthur yet? Something like a modern Canterbury band with some very nice violin in there reminding this Dane of Caravan circa Girls who grow Plump... 

Yes i've just about finished my "best of" lists from 1969 to 2012 which is where i'll stop. It really does depend on my mood as to what i'm into on any given day. The other issue for me in making sub-genre lists is that on the site here every band is under one sub-genre but many of their albums could be under a different one. The Sky Moves Sideways for example is pure psychedelia but they are listed under Heavy Prog. That album isn't Heavy-Prog so i'd have to make executive decisions. Just a lot of work plus it will be so hard to decide an order. We'll see...and yes I do like Syd Arthur, I don't own anything by them but have listened to quite a few tracks on Youtube like the one Pierre put up.
And like you said David it's a nice problem to have all this amazing music to listen to.