For me, Chris Squire's sound has always been one which makes me go 'wow'. I only have two Yes cds on my ipod, the first two LPs, and the bass is superb. It changed over the years but always kept that growl. I never tried to copy it in any way shape or form and the only Yes cover I have ever played was Wonderous Stories which I played on guitar not bass.
My 'go to' tone was always Jack Bruce's sound on the Cozy Powell LP 'Over The Top'. His intro solo on Sweet Poison was an unconscious reference point for years and my second bass was an Aria SB700 because it was as close as I could get to the SB1000 Bruce was using at that time. In 1986, I then got the Percy Jones/John Giblin/Wal bug and bought the Wal Fretless I still use as my only electric bass today. My sound now is probably a kind of Bruce/Giblin mix with strong references to Steve Swallow in my electric Jazz playing.
Other bass sounds that I love include Jaco, Bruford era Jeff Berlin (hate his sound now), Jimmy Johnson, Steve Swallow and Anthony Jackson. I never really tried to emulate the tone of any of this group, though.