I seem to have success with any repellant that has at least 40% DEET. I don't like the way it feels on me, but it does keep them off. If you have sensitive skin I would test it on a small area first, and don't spray it on plastic. It tends to deform it.
I would be interesting to know if there have been studies to see how deer react to the scent of DEET - or thermacell for that matter. Does anyone know?