If we're talking about "the dark side" in terms of a more, commonly perceived, negative aspect... I don't want to put myself out there as some kind of "bad ass" but let's put it this way... it's a great deal of effort to actually show some compassion about people (or living beings) in general. I score, and have scored highly on sociopathic scales and I'm fine with that. I'm doing fine by limiting my social interaction and I enjoy living my life like this. Alongside that; there are hardly any commonly accepted things I care for. I like serial killers and that's probably the mildest of my interests (well, besides that I enjoy painting figures, making props, and doing arts in general)... but if it comes to interests, death and serial killers are the mildest of it all.
As a slight confession; I feel that sometimes it's best for me not to indulge on each and every thread going on, on this or any other forum, because I just know I'll going to smack people in the face verbally in an excessive manner... it wont be a suckerpunch but a wrecking ball. There's part of me I rather just keep to myself for most part. I'm quite sure that if I were to blatantly express ALL my thoughts and interests to a therapist, I'm sure I'd be put away for quite a while (or at least be subject to some serious therapy). I'm fully aware that I'm not normal in that sense. I just have, and as a kid had, a lot of privacy, so I could indulge on whatever obscure interest I had, alongside a few things that were more age appropriate like videogames, lego and whatever you have as a kid. But my weird interests never got away; I remember that as a kid, the thing I did draw most, were torture devices... I vividly remember that in first year of high school we had to design a chair... I ended up drawing up an electric chair of sorts. It freaked out the teacher apparently, but there was no cause for alarm. But that was already years later after taking an interest in such things.
In general I don't think that the interests in itself and as such the interest in such "dark" topics is aspergers, I think the way I experience and enjoy them might be. Imagine it like for instance the numbers breakdown on serial killers... victims, stabwounds, things like that... but alongside that I do spend a reasonable amount of time thinking about why I enjoy something. I can easily spend some time in dissecting why I rather have sex in this position instead of the other in terms of anatomy for example. I tend to create interesting factsheets or diagrams in my head to why I like thing X. That's also a reason why a lot of things I like, stick around for a while, even if I tend to change around the way I enjoy them. Enjoy a different aspect or just enhance them. For such a reason I can watch a movie numerous times and get something different from it each time.
I actually think, on an unrelated sidenote; this is the problem for me to learn new things in school. I'm being told how to view and enjoy them, not to enjoy them on my terms. They wont stick that way.