You have some great tastes in music with these bands, Harks....all were less commercial than what Floyd became, but some brilliant stuff.It makes for a good discussion and in the end, there's no real absolute best as they're all good and it may depend on the impact the albums made upon you.
I do recall hearing Echoes and thinking.....I have not heard this sound before and it made for a terrific lead-in to DSOTM, but by then I veered off listening to other artists that did more for me - Can, Neu, Hawkwind etc.
Nevertheless Pink Floyd were brilliant whilst they had all their components in tact and maybe the mainstream element turned me off them to some degree.
Whichever way though DSOTM was a landmark record and will forever be remembered as such....and rightly so.
Just the drumming by Jaki Liebezeit on this track is worth the listen in itself....this was my first ever connection with Can back in the 70's....blew me away.