If you're not quite ready to take the plunge, there are plenty of options that will still titillate you. You can pick a Hollywood or foreign film that has an NC-17 rating, which is essentially a soft X-rating and is either sought out by filmmakers for publicity or considered the "kiss of death" to features that hope to pull in the mainstream megabucks. Or you can choose from among European and Japanese films that enjoy fewer restrictions on sex and have a more mature, savvy viewership (not to mention legislators), so you'll find, say, French films with sex that doesn't hide—or exaggerate—real interactions between two bodies. Or you can rent a softcore feature, either a B-grade film with male and female nudity (no erections) or one with simulated sex. Or you can watch cable TV or pay-per-view porn. Cable porn is softer than "hard core"—the stuff that shows penetration—though it's very similar because these films are the edited or softened version of a fully explicit porn feature. They show no penetration or genital close-ups—but it's definitely not simulated sex!
If you want to try out some steamy Hollywood or foreign movies, try these Hollywood films:
Basic Instinct (director's cut), Better Than Chocolate, Body of Evidence, Boogie Nights, Bound, Caligula, Crash (director's cut), The Fluffer, Henry and June, A History of Violence, Holy Smoke, The Hunger, Jade, Kama Sutra, Last Tango in Paris, 9 1/2 Weeks, Secretary (highly recommended)
Belle du Jour, Betty Blue, Emmanuelle, Fanny Hill, Hammer horror vampire films circa 1970, In the Realm of Passion, In the Realm of the Senses, Lesbian vampire films by Jess Franco or Jean Rollin, The Pillow Book, Romance, Sex and Lucia, Tokyo Decadence, The Unbearable Lightness of Being, Y tu mamá también