8. Giancarlo Esposito (Gilbert Lawson, Season 3-Digital Estate Planning)
Gus Fring! All Breaking Bad fans rejoiced when the big bad from the beloved show made an appearance late in Season 3 as Gilbert, the right hand to Pierces father. Taking the group into a video game world created by Pierces father, the winner getting his inheritance, Gilbert soon proves to have ulterior motives, and the group must come together to beat him at the game he helped create. Mix in a Breaking Bad reference or two, and that wonderfully heartfelt ending between Gilbert and Pierce, and you have a great use of a guest star.