Community: 10 Best Guest Stars

Nathan Fillion has become a nerd icon. This is due to his work with director Joss Whedon who cast Fillion in arguably his most famous role to date - Captain Malcolm Reynolds - in the short-lived space western, Firefly.

He also appeared in the final season of Whedon's Buffy the Vampire Slayer, as well as his internet miniseries Dr Horrible's Sing-Along Blog. Recently Fillion has starred as the eponymous Richard Castle in the show Castle and is currently starring as John Nolan in The Rookie.

Fillion plays the Head custodian of Greendale, Bob Waite, in two episodes of the show. The first is Season 5 episode 6, entitled Analysis of Cork-Based Networking. Fillion's role in the episode isn't large; he is a cog in the chain that Annie and Hickey have to go through to get a new bulletin board put up. Fillion says he can move their new work order up the list if he can get their porn unblocked. This starts off a chain of favours that they have to go through in order to get the board up.

Fillion returns as Bob Waite in the first episode of season 6, when the show had moved to Yahoo. In the episode, Jeff and Britta turn Shirley's Sandwiches into a speakeasy after a new consultant, played by Paget Brewster, shuts down the sale of alcohol in the school. When Abed visits the speakeasy, Fillion can be seen inside, chatting to Jeff in one corner of the room