After having read all the previous posts, I think I have a few that others haven't mentioned, one of which might be stretch.
Steven, from "Dummy" (played by Adrien Brody)
He's socially awkward, mumbles quite a bit, doesn't seem to be comfortable with eye contact, only has one friend, and has been obsessed with ventriloquism since childhood. Some of the more meaningful conversations he's had has been with the dummy.
Adam, from "Untamed Heart" (played by Christian Slater)
He's a loner, hardly ever talks, when he does he has difficulty maintaining eye contact, is very intelligent as suggested by (apparently) obsessive book reading that results from insomnia, can be socially inappropriate (reference: haircutting scene), is obsessive about his music collection (a few old records he listens to over and over), and even states he doesn't get along well with people. There's more, but I think this covers the gist of it.
This one could be a stretch: Odo from Star Trek: Deep Space 9.
I'm not a big fan of the various Star Trek franchises, but DS9 was one of my favorite shows due mostly to Odo; I could identify with him to a certain extent (before I knew about AS). In fact, it was pretty much a coin toss between him and DZ as my avatar. Also, he's not human (not even humanoid), but he does seem to have some AS traits. I've only recently started re-watching this series on DVD (my memory may be a little shaky), so here's my reasoning:
* Loner. Doesn't like socializing. Doesn't like having uninvited guests.
* Feels isolated. He's the only known example of his species, at least initially. Even when he does find others of his species, he feels different from them.
* Socially awkward. Feels uncomfortable whenever he's in social situations that are outside his comfort zone; i.e., when he's not there in his professional capacity.
* Eye contact. He doesn't always make eye contact with the people he's talking to, and when he does it's more of an intense observational assessment, as if he's trying to analyze what the other person is doing/expressing.
* Observation. He notices small details that others would likely miss. There was an episode where he could tell a woman was lying about crying over her deceased husband because he noticed her eyes weren't red and there was no puffiness around them.
* Obsessive interest. He's the detective on the show, and much of his energy is devoted to that. When asked if there was anything he wanted, he replied that he had his work, what else could he want? He reads mysteries for a hobby, and usually solves them early on (hobby related to his work).
* Uninterested in social interactions. He's said that the reason why people engage in "coupling" was a mystery to him.
* Favors rationality over emotion. Expresses a small amount of disgust over how irrational people can be, but sometimes also seems to imply a little bit of jealousy.
* Meltdowns. I'm not talking about his 17-hour regeneration cycle where he has to return to liquid form. I remember at least one episode when he had a particularly nasty meltdown that involved destroying much of his living quarters when he found out Kira (his unrequited love interest at the time) was in love with someone else (I'll admit, not definitively AS, but coupled with the other traits I think it adds support).
* Routine. At least one episode has made note that he conducts his rounds through the Promenade on such an unwavering schedule that shopkeepers set their clocks to them. In another episode he was a few minutes late reporting for duty and his colleagues commented on how unusual it was for him to be late.
* Devoted to justice. He's obsessed with obtaining justice, even if it means bending the rules; he adheres to his own sense of integrity and honor. He's wracked with guilt whenever he's done something that went against his sense of justice.
* Can be overly truthful. He's never hesitant to say what he really thinks (unless it has to do with the aforementioned unrequited love). In one episode he admitted that all the evidence pointed to him as the most likely suspect in a murder case.
Any thoughts?