Ok, let’s start with the fact that these are Not Safe For Work. That means that there are adult themes and probably nudity, and that there just might be explicit sex.
So, I just ran across a poll of the best NSFW webcomics and while I haven’t read most of them, and some are surely atrocious, A few of these are actually quite good in their own right, and deserving of more attention.
Go Get a Roomie is a funny, Belgian, lesbian strip, that started our with beer (Belgian ale, good stuff) and light humor about casual sex. Since then, it has grown into a romance between a closeted dreamer and the titular bar and bedroom-hopping Roomie (who may be a closeted romantic). It’s not very explicit (bare breasts), but it is sexy, romantic, and clever. It’s in good shape to win, and deserves to.
Curvy is highly original (as are the creator’s other, mostly SFW comics). It’s a surreal, dimension-jumping queer comic (mostly lesbian, but also gay and transgender with some marginal heterosexuality). Candy World, Corporate World, Water World, so-called Smart World… and is our home really “Boring World”? There are some very explicit bits.
Menage a Trois has more mainstream appeal, as it centers around a likeable nerdy virgin guy with several potential love interests (there are characters of all orientations). The art is crisp and vaguely reminiscent of “Archie”, and while the premise (uber-nerd moves in with punk-rock lesbian and an excessively tall, blonde and busty French girl) seems doomed to cliché and stereotype, the comic generally plays off of its clichés well. It’s fairly explicit at times, but nothing you wouldn’t see in an “R” rated movie (a rating it applies to itself).
Way down the list, and deserving of more, well, love, is LovexCore, a kind of alternative-reality take on Jamie Jennings’ (SFW) Lavender Legend, just with vampires. LovexCore is funnier (and sexier?) if you’ve also read Lavender Legend, so you’ve got no excuse not to.
Another title that hasn’t received many votes is Jess Fink’s exquisitely-drawn steampunk comic, Chester 5000 XYV. It’s a story about a love affair between a woman and a mechanical man, with some funny and tender moments, but it’s also extremely explicit: more so than anything else on this list.
Addendum: Oglaf is a strip that just keeps getting better over time.