I voted for my INTP dad and chose my mom's type: INFJ.
Okay, because both [MENTION=8413]Zarathustra[/MENTION] and [MENTION=4877]Kaizer[/MENTION] both repped me to ask me to elaborate: I was operating under the assumption that the thread was asking "INTPs: which type is the best romantic match for you personally?" So because I can't speak for any INTPs except my dad -- because he's the only INTP I know very well, outside of acquaintance-ship, outside of the forum -- I speak for him by saying that, if you were to ask him who his perfect match was, he'd say my mom, because he's a softy and a romantic with well-developed Fe, and he's been with my mom for over 25 years. If I know him well, and I do, I'd say that if you were to ask him this question, he'd say that my mom is the only woman he'd want to spend the rest of his life with, and the perfect woman for him.
But since you frequenters of this thread are mostly NTs, you want analysis! So I'll try to analyze and say: The two of them, INTP and INFJ, have very compatible senses of humor -- though his is goofier -- and they are about equally introverted, and they can read each other very well without having to say anything. Neither is terribly communicative in certain ways, but they don't really have to be, because even if one of them is confused, they can draw the other one out and figure them out bit by bit. They're both very low energy, so their lifestyles are equally sedentary and therefore compatible as well. And, last but not least, there's the obvious benefit of combining a T with an F: one is more nurturing and kindness-focused, and can advise the other on those matters, and the other is more grounded and logical, and can bring the other one back to earth when necessary.
The only downside is that my dad is a 5w6, and because of his 6 wing, he and my mom tend to reinforce each others' conspiracy theories -- and because he's a 5, there's no way to convince him that he isn't being logical.