Since this thread was resurrected and after reading all the posts, it occurs to me just how many people once lived the Skyrim life that have moved on, not looking back. With few exceptions, I recognize none of these posters. But welcome, Joe the 446th! Now, my input on the topic:
I still believe that Sylgja is the most attractive female candidate for wifehood. The most useful would depend on playstyle; for me it would probably be Mjoll, since she's invincible. I'll not that I've never married Mjoll. Maybe some day. Too bad there's not a 'destroy the Thieves Guild' mission.