My understanding is Parlophone is the best for everything from Pablo Honey to Hail to the Thief, the special editions for In Rainbows and The King of Limbs, and with A Moon Shaped Pool and OKNOTOK it's more about having the EU press and NOT the US press - book editions for both would use the EU press, but the indie color variants of the normal editions have separate EU and US presses. Parlophone availaibility is all over the place, in the EU they kept pressing OK Computer and Hail to the Thief basically until XL took over, but Kid A and Amnesiac were remastered several times under Capitol. Best thing to do is look at Discogs and see if the runouts match the originals.
EDIT: And yeah, the Capitol Kid As are not great, because I don't think any of the Capitol Radiohead presses are good. CD masters, URP manufacturing…