In case you missed it, Chris Forsberg is running down his own list of questions (and enlisting the help of many Celtics blogs to do it). So I'm going to quote our own writers and point you to his article for the rest.
Jimmy Toscano, CelticsBlog (Glen Davis)
The sixth man of the year is none other than Glen "Big Baby," "Uno Uno," "Sweet Feet," "The 11th Hour," "Shrek" Davis. I've always been a big fan of Davis. I just love the energy he brings to the game and the effort he gives the entire time he's out there. I'm also assuming that Shaq and Jermaine O'Neal split enough starts that neither one will be considered a certified "bench" guy like Davis will be. When he's in the game he does a lot of little things that bench players should do.
He's the best on the team (per 48 minutes) at taking charges, he's great on the offensive glass and he pumps up the crowd. He can provide that offensive spark that was often needed (and missing) last season.
Greg Payne, CelticsBlog (Entire bench)
I didn't label one single player as the team's MVP, and I'll do the same with the team's sixth man. Bench help at each and every position will be critical for the Celtics this season. Glen Davis needs to come through so that Kevin Garnett can rest. Marquis Daniels needs to stay healthy so that Paul Pierce can rest. The same goes for Von Wafer and Ray Allen, as well Nate Robinson and Rajon Rondo. I can't see one specific bench player distinguishing himself from his counterparts, but that all relates back to the team aspect that the Celtics have thrived upon these past three seasons. Each and every player matters, and bench players are no exception.
Hmmm, I think Greg cheated a little on this question, but we'll give him a free pass just this once.
Bonus link: Celtics Hub calls it a tough choice