Last night I did Harrison Greenbaum and Sam Morril's Don't Touch the Foot show at Sage Theater. It's always hosted by Baratunde Thurston. I've seen Baratunde host a couple of times now and I think he's really great at it. He's a funny guy but what I think he really excels at is the not-funny part of hosting. He gets the crowd to feel like a unit instead of individuals. He's really conversational. He finds out who people are, where they're from, how they found the show, etc. but without doing it in an annoying way. He really builds up the energy before intro'ing each comic and gets the crowd to applaud and make noise without badgering them too much.
And he did a really key thing last night: He got a sparse, spread out room of people to all get up and move to the front couple of rows so it felt more like a cohesive crowd. A little thing like that can really make or break a show.