If strictly speaking for GMs, I like Paul Heyman best with his thick pile of backstage stipulations which I try to make use of each and single one (including falls count anywhere).
On another note I like Mystery Wrestler with the hidden ECW and nWo enforcers that jumps out when you drop your T-shirt.
Lastly for cheap thrills, Sheriff Austin playing an abundance of pre match with "draw seGMent" in the text to open as many enforcers as possible to build up for his Mid match winning card is fun too. p.s. his ability work so well with No Way Out TB to avoid opponent from spinning a reversal for its effect