Acucullophilia is a fetish for people who are circumcised or for other aspects of circumcision. A person who has this sexual preference is known as an acucullophiliac. A person with acucullophilia is likely to pursue a partner who has been circumcised, both for relationships and sexual encounters.
While acucullophilia is likely not a very common fetish, surveys have found that women express a preference for circumcised penises in male partners. Research around gay men's opinions here are scant, but may be generational. Note, however, that by definition, a fetish means not just a preference for circumcision, but a very strong fixation on it, or even a need for it in order to achieve arousal and gratification.
The biggest difference between a circumcised and uncircumcised penis is in appearance - the head of an uncircumcised penis is covered in foreskin when it's not erect. The foreskin retracts and almost disappears when the penis is erect. With a circumcised penis, the foreskin covering the glans of the penis is removed, leaving the penis permanently exposed whether flaccid or erect.