obviously, Ororo Munroe
Pre-Phoenix Jean Grey, but with post-Phoenix arc powers... if that makes any sense. You have nothing to fear from your telepathic significant other if you're honest from the beginning, plus I doubt Jean is the type that just barges into your mind every two seconds. I thought there was some unofficial oath Xavier had his telepathic X-Men take. To never read another person's mind unless they had permission or there was some crisis that deemed it necessary. Then again, recent comics have turned Xavier into a two-faced, manipulative piece of crap and a third of his X-Men into bipolar, militaristic--
Whoa, I got off-topic. Anyway, I choose Jean. Telekinesis would be fun to have for, um, many reasons. Telepathy would be even more fun and quite frankly very useful too. Not to mention it's possible that a telepath with her level of power and control can not only technically be immortal (possess another body?) but can do the same for another person. Even barring this option, just imagine how much she could help you. Feel run down and mentally exhausted? Just let her pep you up. Realize you have a bad habit that's really hard to beat? She could theoretically just erase it from your mind. I know, I know, it's not the brave and most rewarding way out of such a thing, but it's a possibility that's there. Ignoring her powers for a moment, she is a kind and strong individual, giving and smart. The girl next door with maybe a hidden wild side? Plus she's a redhead. :p
I would settle down with the Stepford Cuckoos, triplet blonds in a state of ageless adolescence sharing a mutant hive mind with one another and personally groomed by Emma Frost herself.
And if you need any more proof that I'm right...
This all the fuking way.