I'd start off with Disintegration. Have seen Fat Bob and Co more than any other band apart from Pearl Jam. His voice isn't the strong point of the band but many great songs, especially on the trilogy of Pornography, Wish and Disintegration.
When I first listened to Kid A I thought it was almighty shite. A few years later I listened to it again and realised I had made an almighty error of judgement.