How's this for a good reason to walk down the isle. A new recent study published in the journal BMC Public Health claims that men without a mate are 35% more likely to die from cancer than their married counterparts. From WebMD:
Researchers tracked the number of cancer deaths for 13 common cancers, including breast, prostate, malignant melanoma, colon, and lung, in more than 440,000 Norwegian men and women over a 40-year period from 1970 to 2007.

... the never-married men were 18% more likely to die from cancer than married men.  More recently during the 2005-2007 time period, never-married men were 35% more likely to die from cancer. Never-married women during the 1970-1974 study period were 17% more likely to die from cancer than married women.  During the 2005-2007 time period, never-married women were 22% more likely to die from cancer.
Overall, the study showed that single men and single women fared the worst in their cancer outcomes; those who never married had a greater risk of losing their life to the disease compared to those who had tied the knot, divorced, or were widowed.