Hosting Highlight: In his 2006 opener, O'Brien dropped by that year's buzziest shows. His flirtation with Pam (Jenna Fischer) at Dunder Mifflin? Perfection.
Hosting Lowlight: After hosting the show in 2002, he co-hosted with Ellen DeGeneres, Brad Garrett, Darrell Hammond, George Lopez, Bernie Mac, Dennis Miller, Garry Shandling, Martin Short, Jon Stewart, and Wanda Sykes in 2003. We don't know why the Emmys couldn't learn this lesson earlier and spared us the 2008 reality TV multiple-host debacle, but there's perhaps a lesson in this for all of us: Just say no to more than one emcee.
Lessons Learned: As evidenced by his earlier appearances, as well as his critically successful 2006 stint, hosting is a gig where the late night comedian thrives. Based on O'Brien's example, Kimmel should plan to let his real enthusiasm for television come across and not be afraid to be a fan as well as an insider. —Erin Strecker