Let me see, just taking into account menus/UI..
- PES 3 is really cool. I agree with
@MKC, it has a nice "computer" late 90's early 2000's vibe about it.. Kinda like the Matrix. I like it.

8/10
- PES 4 is a pretty clean design.. Nothing special but functional nonetheless. 6/10
- PES 5 and 6 seem pretty similar to me. I think it's pretty functional and it has some nice background images. 6.5/10
- PES 2008 is a mixed bag. I really like the little details like more crowd animations, benches, team pictures, fan pictures. But I'm not a fan of the main menu. 7/10 (just because of the nice additions, if this had a different main menu it would definitely be higher up the list)
- PES 2009 is cool. I like the "graffitti" style, really reminds me of the "Indie Rock" vibe. Pretty streetwise and youthful look. Fun and different 8/10
- PES 2010 I love the whole "rotating circle" thing. It works really well for me. Nice background pictures too! My favorite menu in the series. 9/10
- PES 2011 has beautiful backgrounds and really polished finishes and effects. 8.5/10
- PES 2012 is my least played PES, if I remember correctly it was similar to 2011, but with downgrades. 7/10
- PES 2013 has some really nice touches, especially in ML I liked the shots of the team training with the manager. But I agree not as beautiful as 2011. 6.5/10
- PES 2014 is the most basic one. I like the idea of showing the player's faces, but otherwise way too basic. 5/10
- PES 2015 menu is functional and pretty. I like the animations in each box. But a bit cluttered. 7/10
- PES 2016 same as 2015. 7/10
- PES 2017 I like the screenshots they used for the different modes, nice and straightforward. This is my favorite PES but in terms of menus it's a downgrade from 2015 and 2016. 6/10
- PES 2018 Same as 2017 but with bigger pictures. 6.5/10
- PES 2019 Even though I really like this game as a whole with gameplay mods, it has a boring UI. What's up with the grey background, very very dull. 4.5/10
- PES 2020 and PES 2021 were an improvement in that the pictures covered the background. A bit too simplified though. 6/10
- efootball That overall aesthetic is just.. insanely ugly. 3/10