...but with a couple twists.
First, I'd like the storyline to begin just before the calamity, invasion, or whatever brings the world down. Part of the fun of The Stand, for instance, is we got to see how the characters reacted to things falling apart, rather than just seeing the post-apoc world.
Second, I do have some limitations on possible end of the world scenarios. I'm not big on anime-type stuff, or weird scenarios like everyone turning into sex fiends or into animals or whatever. So possibilities include, but are not limited to:
1. Plague of some kind.
2. Techno-collapse (machines stop working, electricity disappears, etc.)
3. Revolution or social disorder
4. Alien invasion (as long as aliens are humanoid...I'm more into the subtle kind of invasion a la They Live than flying saucers de-orbiting and blasting everything to rubble like Independence Day or War of the Worlds). "Aliens" could include demons.
I'd like a good mix of role-playing, storyline, and sex. I have few limits on sexual content, so anything from romance to hardcore non-con sex is fine. I'd probably play a female character, but could be persuaded to play a nefarious male character or characters under the right inducement.
I do definitely want plot, and gritty realism.