As with sex itself, the better parts of HBO's long-running magazine show Real Sex are a matter of personal preference. However, the cable channel's official greatest-hits package, The Best of Real Sex , is an accurate overview of the series' polymorphic interests: loving intimacy, outright orgies, voyeurism, transvestites, computer sex, self-pleasure. The more sensational stuff, such as a story on a Miss Nude World competition or a software company's development of cyberslut "Virtual Valerie," wears thin after a few minutes. But when the accent is on ordinary people with ordinary bodies, The Best of Real Sex is far more compelling. The first feature, for example, concerns a course in helping women of any age experience their first full orgasm through masturbation. Elsewhere, a Maui retreat presents a New Agey curriculum to individuals and partners for deepening their sexual experiences though much of the footage looks like a carnal free-for-all.