So let's start out with the favorites:
Roy Halladay, Cliff Lee, and Roy Oswalt. Sure an argument could be had that Hamels is better than Oswalt, but Cole's status as a mental midget moves him into the 4 slot in the rotation. They have 3 Cy Young's split between the first 2 starters and all 3 of these guys are Cy Young contenders every year.
Let's get their career stats out of the way, all of these will be respective to Halladay/Lee/Oswalt:
Career Wins: 169/102/150 (about 16 wins a year average for each of them)
IP/162 games: 235/218/221
Career ERA: 3.32 (lots of time in the AL East)/3.85/3.18
Projected 2011 WAR: 6.8/6.7/4.1
Each of these guys has put up absolutely insane career numbers, we can all agree on that. They are all on the back side of their careers though, which is the big negative against them. Will these guys be producing at the same level 3 years from now? Most likely not. There is sure to be some regression, especially in Oswalt's case, from their career numbers. These guys are also making a ton of money with a committed $253 mil will be made between them after the lives of their current contracts.
After you look past their negatives and just look at what they will do on a baseball field, this front 3 may be one of the best ever. Look at those projected WAR's (all roughly similar to what they produced last year). Other teams in the NL East may just want to start playing for the Wild Card right now. Halladay carving up the opposition with pinpoint control and dazzling pitches, Cliff Lee's utter dominance from the left side, and Oswalt's mix of power and control will make this a tough series every time you face the Phils this year.
San Fransisco Giants
Tim Lincecum, Matt Cain, and Jonathan Sanchez. These 3 showed their ceiling in this year's playoffs. They each beat some of the best pitchers int he game in a heads up matchup. Hell, I think they actually beat every pitcher from the above rotation head to head. Oh, and don't forget they are all young and signed fairly cheaply. Now a look at the numbers:
Career Wins: 56/57/34 (16/11/10 for 162 averages)
Career ERA: 3.04/3.45/4.26
FIP: 2.86/ 3.84/ 4.08
Projected 2011 WAR: 6.9/4.6/3.2
Sure their numbers are not what the Phillies' staff boasts, but you can not argue with their production from last postseason. Also, this staff may be the most fun to watch out of any. The electric stuff that each pitcher has is dazzling. They may not be as good as the Phillies but they are almost there. Seeing that each of these guys is under 29, the Phillies may want to watch out in the upcoming years.
Zack Greinke, Yovani Gallardo, and Shaun Marcum. A prediction before I even look at the numbers: these guys won't even be on the same planet as the staffs of the Phillies and Giants. However, the jump in numbers from going to the NL from the AL (especially the East) for these starters should not be undervalued. Shaun Marcum pitched exceptionally well against the Yankees, Red Sox and Ray all year last year. How do you think he is going to fare against the Reds, Pirates and Cubs? Greinke has gotten some of the least run support of all time the past 2 years. Now he has Prince Fielder and Ryan Braun hitting for him. The numbers:
Career Wins: 60/36/37 (11/15/12 for averages)
Career ERA: 3.82/3.67/3.85
Projected WAR: 6.3/4.6/3.6 (Gallardo's was last years WAR numbers)
Actually, my prediction was a little bit off. The only category that the Brewers' staff pales in comparison is in the Innings Pitched. I believe that most of these guys have been limited by youth and their innings purposely limited. Now that they are all getting to the middle of their careers and their peak years, I would expect those numbers to increase. I'm also not sure if the projected WAR's factor in the shift to the NL. Logically, they should, as facing the pitcher slot and a host of inferior talent should provide a boost to one's value. Although WAR may just be based on FIP which already takes those into account. Pardon me for my lack of knowledge on the subject.
Regardless of the WAR debate, surely their numbers will improve from their career numbers. Facing worse competition (Marcum), having better offensive support (Greinke), and not having to face the opposition's #1 (Gallardo) will surely help their Win numbers (I know it is a bad stat, but the influence of those outside forces are the reason it is a bad stat). I may not put them on the Phillies level, but I would definitely be wary of this pitching staff next year.
St. Louis Cardinals
Adam Wainwright, Chris Carpenter, and Jaime Garcia. While Wainwright and Carpenter have had some injury riddled pasts, it should not exclude them from this discussion. These two have proven to be some of the best in the game, when healthy, and deserve to be mentioned on this list.
Career Wins: 66/133/14 (Average: 15/15/14)
Career ERA: 2.97/3.80/2.96
Projected WAR: 6.6/4.1/3.2 (last year's numbers)
None of these guys are as electric as most of the pitchers listed before, but Carpenter and Wainwright have proven they can do the job and Garcia is an interesting young pitcher. While they, too, are not on par with the Phillies, they should be very interesting to follow. (Side Note: with the addition of Big Puma's mammoth... um... bat, I would expect the Cards to score at least 3 runs more per game than last year. Yeah, that is how good Puma is.)
Overall, none of these teams can match the Phillies, but it looks like the NL is about to face another year of offenses putting up dismal numbers.