#1
What do you guys think are the best Radiohead albums? This is what I think:

1. The Bends tied with OK Computer. Two of my favorite rock albums of all time. The Bends is extremely well put together and has really catchy chord progressions/melodies. And the guitar tones on that album are AMAZING! OK Computer needs no explanation, really.  

2. Kid A tied with In Rainbows. The order of tracks on Kid A is perfect, and In Rainbows has phenomenal songwriting. However, Kid A could do without Treefingers, IMO.   

3. Hail to the Thief tied with Pablo Honey. I believe Pablo Honey deserves more attention. Some tracks on it are really well written, like Blow Out or You, and others just make me wanna get up and dance, like ACPG or Ripcord. However it is quite unoriginal, so that's why it's at #3. About HTTT, Sail to the Moon is what I would call musical perfection, however, it can be quite boring at some times.  

4. A Moon Shaped Pool. I absolutely LOVE Present Tense and Daydreaming, but the rest of the album (except for Burn the Witch) is a little forgettable. 

 5. The King of Limbs. The reason it's at #5 is that it doesn't really feel like an album to me. It feels more like a collection of good songs put together, and the order of the songs wasn't given enough thought. Give Up the Ghost is beautiful, though. I like to listen to the Basement Session to replace it.  

6. Amnesiac. All of the songs on this album were uninteresting to me except for Pyramid Song and I Might Be Wrong.  

This is just my opinion. I would like to hear what your opinions are!
#2
Radiohead is my favorite band =)

1. Kid A, simply is my favorite. 
2. Ok Computer, fantastic reccord. I just think Kid A is put together better
3. Amnesiac, it took me time before enjoying the reccord ( 3-4 years) but it is now one of my favorite. It definitely has its slow/weird moments, so I need to be in a certain mood to enjoy it from beginning to end
4. In Rainbows. Fantastic reccord, but as it is explained at the bottom of my answer, I do not care that much about "not easy to understand" lyrics. The music is beautiful though. Some of the B-Sides were magical
5. Hail to the Thief. LOTS of great songs but it has too many. The reccord shout in every direction
6. The Bends. Honestly, I kinda grew tired of those songs compared to the songs on the other reccords. It has been a while since I have listened to 4 The Bends song in a row
7. A Moon Shaped Pool. Meh. The album is well structured but the songs are kinda forgetable for me. Present Tense is a masterpiece though. It could be one of the best song they ever wrote. I really liked the live version of Identikit before they released the studio version. Same goes for the acoustic version of True Love Waits.

Never listened to Pablo Honey

I have to say that even if I my english is excellent, since it is not the first language I learned, I do not really pay attention to english lyrics, unlike I would do with a french song. The lyrics I enjoy the most are very simple ones. Let Down and How to Disappear Completely are the best exemples.
#3
local_hero 

Hello! My initial list has changed. It's now something like this:

1. OK Computer
2. The Bends
3. Kid A
4. In Rainbows
5. Amnesiac 
6. Hail to the Thief
7. Pablo Honey
8. A Moon Shaped Pool
9. The King of Limbs
#4
I would say something like this: 
 
1. Kid A
2. The Bends
3. OK Computer
4. In Rainbows
5. Amnesiac tied with Pablo Honey
6. Hail to the Thief
7. A Moon Shaped Pool
8. The King of Limbs

I agree, Pablo Honey and The Bends are underrated. 
#5
1. OK Computer
2. How Am I Driving EP
3. The Bends
4. Kid A
5. Amnesiac
6. My Iron Lung EP
7. In Rainbows
8. Pablo Honey
9. A Moon Shaped Pool
10. Hail To The Thief
11. The King of Limbs