Based on the 300+ comments in this thread, the nominations for worst contracts in MLB are listed below (at least three recs). You may vote for as many as you'd like, although I encourage you to shoot for about ten. If you think there are six definites, just vote for six. If you think the 10th through 13th spots are indistinguishably bad, then vote for 13.
No, there aren't any more specifics than "worst MLB contract". Interpret it how you will -- worst decision at time of signing, worst remaining contract, most money wasted, dumbest -- whatever.
The poll closes Wednesday at midnight EDT.