Which thermal paste

I am planing to clean my GPU and i dont know which thermal paste to use i dont want it to be conductive because i am fairly new at this and i dont want to destroy my GPU

MY GPU is : gigabyte nvidia geforce gtx 260 oc
 


That isn't really overheating GPU are usually good to 80C. But that card is going to work hard it is an old card with a new game.
 


2 weeks ago i played fifa and it didnt go over 60C