The Simpsons: 10 Best Guest Stars Ever
3. Kelsey Grammar
I had to put Kelsey Grammar on this list simply because of how popular his role as Sideshow Bob became. Grammar is best known for his two-decade portrayal of psychiatrist Dr. Frasier Crane on sitcoms Cheers and Frasier, but is also famed for his role as the malevolent clown-turned-criminal Sideshow Bob on the Simpsons.
Grammar's character, formally known as Robert Underdunk Terwilliger, is one of the most-recurring special guest stars having appeared in multiple episodes in a speaking role and been featured in even more.
In nearly every instance, he attempts to murder Bart Simpson, who exposed his plan to frame Krusty the Clown for armed robbery of the Kwik-E-Mart, but is always thwarted by some mishap or other, our favourite being the stepping on the rakes.