I found this fascinating quote today:
Nathan Fillion has, in the space of seven years, risen to the status of a geek icon. Beginning with his best-known role as Captain Mal Reynolds on Firefly, his work on several of Joss Whedon’s projects has transformed the former soap opera actor into a huge draw for the geek crowd. But there’s a lot more to Fillion than tight pants and a pistol — and a heck of a lot more than a shirt with a picture of a hammer on it.wired.com, Interview: Nathan Fillion Talks Firefly, Dr. Horrible, and Why Kids Need to Read, Jan 2010
You should read the whole article.