I always loved the ST:2-6 uniforms...but yeah, I always kinda imagined them to be the dress uniform (the crew always was in for no apparent reason)...and there was a standard duty uniform that we just never saw....
(And we should have seen a REAL intermediary uniform/s between the TOS-movie & TNG series! I think something even *like* that collarless jacket would have worked - but as a shirt/tunic with the TNG colors instead.)
To be honest, I think the TMP uniforms make the most sense...and there was a lot of variety in the styles -- I just hated the color pallet... In the TNG cast episode of family guy, there was a dude sitting next to Stewie at the Trek convention who was wearing a TMP-style uniform but with *red* color...I thought it looked pretty cool. (I'll try to hunt up a pic somewhere...)
I think that the ENT uniforms looked pretty believable and practical for their time period (probably the most realistic of them all, actually!)
I loved the TNG's season 3-onward uni's at first sight. (I hated the season 1 & 2 outfits...*awful*...)
I liked the DS9/Voy variation...I just got tired of them after a while - esp. when everyone else had switched...they looked old after that - but in retrospect, I still like them alot. I wish in Voy we would have gotten a mix of both late TNG *&* early DS9 styles - like we got in Generations. Mix it up a little, I say...(that one thing I read the designer of the TMP uniforms was going for - variation in uniform cuts...)
I *NEVER* liked the TOS uniforms! But oddly, I *LOVE* them now in the JJ Abrams movie version!