I don’t have a SO currently, but looking back on my past SOs I can say that I tend to go for guys who are opposite of me, at least in looks. I’m 5’5, blonde, and fair skin; who I have dated in the past most have all been at least 6’4, black or dark brown hair, and dark skin. I read somewhere that people tend to go for the opposite of them in looks because if you have a lot of sampling of gene types, the children will be healthier. because they are diverse in genes. (Or something like that, I could be botching it)
As for being opposite of your partner in personality or interests, I find that to be exciting. I like it when you can learn something from your partner. I have a friend who is the complete opposite of me (gender, looks, personality, interests, hobbies, even family structure, etc) We rarely talk about something I already know everything about. And if I do, it’s nice to get a different perspective on something.