The following is a blog on fictional or nonfiction TV, film and comic characters I feel are autistic or have traits on the spectrum as I'm also one on the spectrum. The first one being the Eleventh Doctor from the long running BBC series Doctor Who played by Matt Smith.  I feel I can relate to his social anxiety, curiosity, immaturity and feeling alone all of the time and purposefully aliening himself due to screwing up all of his relationships. Also he's easily VERY ADD much like Tennant's. He also seems to not understand sarcasm and yet use a lot of it. 
The second being Abed from NBC's Community portrayed by Danny Pudi. The show even makes jokes towards his disorder/spectrum he's VERY obsessed with American pop culture, a history of being bullied and has a dysfunctional family. He also doesn't understand sarcasm and compares everything even Jesus to movie portrayals and other characters. He also has problems with emotions. All of which I relate to as an aspie.
In the SyFy series Eureka the character Kevin, Allison Blake's son has been diagnosed with autism. He has very clear autistic characteristics such as being incredibly anti social and incredibly smart and scientific minded.
In the CBS sitcom The Big Bang Theory one of the main characters Sheldon Cooper displays many clear autistic tendencies. I admittedly am not a big fan of The Big Bang Theory I've always been a Chuck > Big Bang Theory fan so I can't really get into specifics. 

Marshall from the former Showtime original series United States of Tara seems autistic. Though in the same sense Abed from community seems to be given his introversion and love for movies, both of which I relate to. I don't know I may just be adding this one to bitch about Showtime canceling the show. A show written by an Oscar winner, produced by Steven Fucking Spirlberg and staring Toni Collette, Patton Oswalt and featuring Eddie fucking Izzard.