I've had two girls, three boys.. Overall the boys were more affectionate, but it depends and they have very different backgrounds.
Zakk- came to us at 6 months, was left in apt after evictions.. Affectionate at night, big time, mostly too hubby.
Rocky- shelter kitten, was sickly, extremely affectionate and needy.. Fond of giving urgent kisses at night..
Suzie- semi-feral, rescued as 12 week kitten, skittish, not affectionate with humans.
Cookie(male)- littermate to Suzie but way different- skittish, friendly but not overtly affectionate.
Tribbles (female) Found as a 4 month old stray. Will snuggle and purr at times if you hold her close to you if she is in the mood, but not overtly affectionate, friendly and fiesty.. She was more snuggly when she first got here and wasn't feeling well, now she is getting out all that kitten energy!!