It's the crazy bleep bloop, deep throbing wubwubwubwubwub, climaxing synths and massive mind altering bass drops.
I like Dubstep, Grimey if I'm in a rough angry mood, Liquid dubstep if I'm feeling melodic and remixes are almost always fun.
What a lot of people do not understand, is that you NEED speakers that can do low bass to get the most out of dubstep. Like way low, lower than earbuds will get you, like as low as you can go. 25-30Hz is good enough. I see a lot of complaints on youtube about dubstep being nothing but electronic distortion, what I think is happening is those listeners headphones/speakers are failing on the low end and making things sound distorted.
I've been looping Sound Remedy remixes for a couple of weeks now. Kinda like dubstep remixes but not... hard to explain.
If you have a system or a decent set of cans give this a listen.
[youtube]http://www.youtube.com/watch?v=jQJGK0ccLh0&hd=1[/youtube]
[youtube]http://www.youtube.com/watch?v=t1wjL4BqXlI&hd=1[/youtube]