Today I thought:"Why not add some Wilson screencaps?" - but then I had no idea which episodes had already been added by users and which not.
I didn't want to trust only the keywords, because sometimes people forget to keyword pictures, so I looked through all the pages of screencaps and wrote down a list of episodes I found screencaps of.
And if anyone else wants to add screencaps, they might find this list useful. :)

ALREADY BEEN ADDED TO THE WILSON SPOT:

Season 1
-1x01
-1x11
-1x12
-1x19
-1x21

Season 2
-2x02
-2x05
-2x06
-2x07
-2x09
-2x10
-2x11
-2x12
-2x13
-2x19

Season 3
-3x01
-3x02
-3x03
-3x07
-3x09
-3x11
-3x14

Season 4
-4x11
-4x14

Season 5
-5x08
-5x13
-5x20
-5x22
-5x23

Season 6
-6x03
-6x07
-6x10

I found screencaps of these episodes - can't guarantee that the whole episode had been added or just a certain scene. I might have missed something...I'm only human, but just tell me and I will add it.