I'm not too picky about physical appearance, but I'd prefer someone who's taller than me. Good hygiene is also quite important.
As for personality, a willingness to cuddle is a huge plus! And it would also be quite nice if they were open to playing video games or partake in some other nerdy interests with me. Beyond that, I'd also prefer if they had a somewhat low libido since my own libido isn't that high.
And when it comes to gender, I don't really have a preference.