I agree that they are pretty great and they keep changing and evolving...all good. As far as being truly inventive though...if you REALLY believe that, you need to buy more albums. Yes...they're inventive, but there's very little on Kid-A or Amnesia that has been done by others over the last 30 years. Brian Eno was one of the people doing similar stuff back in the 70s and there have been many others since. Radiohead is adding to that history and making it more popular, but there is a precedence for that sound.
Radiohead read on
Ok they are a rock band and with OK computer they won lots of critical fame. But with kidA and amnesiac they have created truely great albums. I think that they have recorded these albums in new and inventive ways and the sound quality or misuse of it is amazing. They have also pushed the musical boundries with the content and delivery of their music. I should also state that I am not such a big rock music fan but these albums are emotional inventive and intoxicating and force me to want to listen. What do you think?