Sabathia vs Beckett - Beckett is the better pitcher in my opinion, but Sabathia is gonna give you another 20-50 innings. Sabathia has a big body, so it will be interesting how it holds up under his workloads as he continues to get older, but there aren't any major red flags yet.
Vazquez vs Lester - This one is a bit tougher, but year to year in the past 3 years Vazquez has been better. Vazquez will be facing tougher competition now, but with the data we have I can't say Lester yet.
Burnett vs Lackey - Burnett is the hands down better pitcher, but considering he's also much healthier this one is pretty easy to decide.
Pettitte vs Matszuka - Matsuzaka has been an overrated pitcher sine coming over from Japan. He's run a career 4.53 career xFIP. Now, that's a quality pitcher, but it doesn't really make me think he's better than Pettitte. Even with Pettitte being much older, Matsuzaka isn't exactly a picture of health. Pretty easy selection again.
Joba/Hughes vs Buchholz/Wakefield - This one is tougher. I'd probably just put this as a tossup next year, but if we're talking about future then I think you have to pick the Yankee duo because I'd take a gamble on both of them in the next 5 years than just Buchholz. I wouldn't fault anyone for picking the Boston duo, though.