When I started looking at this area, I was debating between placing Boston or New York at #1 but obviously changed my mind. The Red Sox are behind at the ace spot (Lester versus Sabathia) but are stronger at the 2/3 spots (Beckett/Lackey) versus (Burnett/Pettite). The biggest question mark in the Red Sox rotation is Dice-K but I think they get more out of Bucholz than the Yankees will with whatever their 2010 version of the Joba Rules are.
The Rays don't have a full on ace pitcher (which is why they don't get the 1-spot) but they have greater depth in the back of their rotation (Davis/Niemann) who while they may not be as familiar to baseball fans as Javier Vasquez (no way he repeats his 2009 performance) and Joba Chamberlain (not sure what the Yankees will do with him this year but whatever it is is likely to backfire)
Overall, the Blue Jays/Orioles rotations are nothing to write home about. I don't see Millwood repeating his strong 2009 performance....there's no way Guthrie would be the #2 starter for a contender. On the same token, nothing really excites me about the Blue Jays rotation. The Orioles avoid the cellar because the young pitchers they have (Bergesen/Matusz/Tillman) have more talent/potential than the Blue Jays starters and there's a solid chance at least one of them (either Matusz and/or Bergesen) are on the cusp of a breakout season.
Who would you rather have with the game on the line.......Rivera or Papelbon? That's a very, very tough question. The Red Sox and Yankees have the back of their bullpen anchored by two of the elite closers in the game, this one is a toss-up. The arbitrary factoid that gives Rivera the nod as tie breaker: He enters the game to "Enter Sandman" by Metallica. That also happens to be the ringtone on my cellphone.