@nitsua60 apart from that I have a soft spot for him, he's super expressive, both vocally and physically, when playing an NPC. He flings his arms out and walks around the room if he's NPC is in a huff, puts on voices, just gets really into it.
I think the thing that I like most is, rather than just saying "You notice Robert is constantly looking to the corner of the room" or giving verbal hints, he plays the character and just flicks his eyes to the left a lot. If we don't pick up on it, too bad, it means we're not paying attention to what the character is doing.