If you don't know who "HRG" is, then turn in your nerd card and move along. However, if you realize that "HRG" is "Horn Rimmed Glasses," the marvelously complex villain (or is it hero?) on Heroes, then proceed.
HRG is played by Jack Coleman, who first came to TV viewers attention as the second Steven Carrington on Dynasty, one of TV's first openly gay characters. (And amusing how Dynasty took the tactic of old school soap operas -- "the character of Steven Carrington is now being played by..."). Jack bopped around H'wood for a while, doing guest shots and movies before finding the role of a lifetime on Heroes, which he simply knocks out of the park every single Monday.
I love it when actors from shows you adore in interviews and commentaries come across as real people -- funny, self-deprecating and actually grateful for the work they get, rather than arrogant prima donnas that actually turn you off from the show. (Examples of people who "get it" and you could see yourself having a beer with include Nathan Fillion, Ben Browder, Jason Bateman or Amanda Tapping. Just seek out a few of their interviews or listen to their DVD commentaries).
TWOPers have probably already listened to this, but if you haven't and you're a fan of Heroes, check out the podcast interviews with Coleman here:
Also, there's a nifty feature at NBC.com where you can watch an episode of Heroes in one "pane," and see/hear episode commentary from the cast in the other. Any of the ones with Coleman would be worth your while, as are ones with Parkman (Greg Grunbery) and Sylar (Zach Quinto).