I thought they were both Itsuki. Maybe because Kyon is usually staring blankly instead of smiling. =P

They ARE from Haruhi Suzumiya :p. Itsuki is the one on the avatar and Kyon on the signature. They are stills from the Haruhi-chan show that's showing on youtube.

Who's that character in your avatar and sig? He looks like someone from The Melancholy of Haruhi Suzumiya.