I was faced with this dilemma in a 12 team 5 x 5 keeper draft. At pick #24, I chose Wood because he will have the highest amount of K's. He will have the worst WHIP of the three, but I like the Cubs team (now even better with Maddux) and I can see Wood winning near 16-18 wins.
I stayed away from Halladay because of being in the AL East (Boston, NY, Balt.) as well as throwing so many innings the last two years.
I stayed away from Vazquez because of AL East (Boston, Balt.) and I also wasn't sure how he would react being in the spotlight of NY.
I may have made an unpopular decision amongst other readers, but I think all 3 would make great anchors of a staff.
BTW, in our draft, Halladay went #26 & Vazquez went #28.