Pure sexiness? I'd say ENFPs and ESFPs easily won the contest...
ENTPs/ESTPs are not bad, though, but a bit too tricky sometimes, unless they have a good Fe...
ENTJs are rare beasts, but they are mighty!! They scare me as much as they fascinate me.
However, the types I feel the most attracted to are slightly different.
I've noticed I get along pretty well with INFJs. I don't understand why, but it works. I like their paradoxes, they often are deep, complex creatures, and they energize me like no others. They are my favorite type.
In some INTJ's, there's something irresistible with their awkwardness, paired with their extensive knowledges and their soft Fi spot.
I also had occasional crushes on some INFPs. Healthy and playful INFPs are a pure delight to meet, and it's the type that makes me feel the most comfortable.
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The less sexy types??? Well, it would sound cruel to make a ranking. But I'd say INTPs and ISTJs, any type with a really underdeveloped social skill. I'm attracted to intelligence, though, but such gift is pointless if you do not know how to share your ideas.
An INTP/ISTJ who could understand how others feel could potentially be one of the most interesting type ever, but alas, this is rare. Their love is very strong, pure and genuine, but they have to learn how to show it.