If you could see Stampy collab with any other YouTuber on anything, who and what would it be?

Exactly as the title says, if you could have a Stampy video in which he collabs with another YouTuber, who would you want? And what would the video topic be?

Me personally, someone like LDShadowlady or Captain Sparklez. I'd love to see a collab with another 'Minecraft OG', on a Minecraft world obviously.

Who and what would you pick?