McCutchen (2.07 '08) was pretty good for me (dealt this year for Kershaw). My best FA pickup was probably CarGo - just sitting there at the end of the only season I didn't win the regular standings.
EDIT: Posey wasn't bad either, drafted in at 2.1 in '09.
EDIT: ...nor was HellBoy at 4.1 in '09.
LFoD '08 [1st/3rd], '10 [1st/3rd], '11 [1st/2nd], '12 [1st/1st], '13, [1st/2nd], '14, [1st/1st]
BRAL '09 2nd, '10 1st