Jon Hamm
Mad Men actor Jon Hamm has had a long line of relationships but none of them stuck. His longest and most notable relationship was with Jennifer Westfeldt. They were together for nearly 20 years until they broke it off.
Now, at 49, Hamm is back on the market. It really doesn't seem like he will be down for marriage any time soon. He's got four or five movies in the works, anyways!