Guests on The Big Bang Theory: Where Is That Person From?

Premiering in the fall of 2007, The Big Bang Theory features a ton of familiar faces. Principals Johnny Galecki and Melissa Gilbert were the on-again, off-again high school romance on the sitcom Roseanne. You may also recognize Jim Parsons from his bizarre 2003 Quiznos commercial or Mayim Bialik of Blossom fame.

What about the cameos and guest stars? If you are frequently left asking "Who is that guy?" or "What else was she on?", you're not alone. Here's the lowdown on those faces you can't quite place.

Stan Lee

Considered a God in the comic world, Stan Lee has been around before the pretentious phrase 'graphic novel' came into modern parlance. However familiar you are with his work, you may not be acquainted with his face. Lee appeared on season three, episode 16 entitled The Excelsior Acquisition. Sheldon is rabid to see him at an appearance in a comic book store, only to be stymied by a traffic court appearance and being subsequently thrown in jail.

Brian George

Does Raj's dad look familiar? He should. The actor, Brian George, portrayed the restaurant owner Babu Bhatt on Seinfeld. His voice is much better traveled, having been used on movies and video games galore. The list is as long as your arm and includes such projects as Baldur's Gate, Everquest II, and Star Wars: Knights of the Old Republic.

Katee Sackhoff

Named one of the sexiest women of sci-fi by yours truly, Katee is better known for her role as Kara "Starbuck" Thrace in Battlestar Galactica. Appearing in Howard's masturbatory fantasies, she counsels him about dating and relationships with a sharp wit and perfect comedic delivery. Don't let the big hair fool you, it's Starbuck! If you watch TV out of order using DVR or TiVo technology, you may also be recognizing her from the series 24 where she plays Dana Walsh.

Wil Wheaton

Considering Star Trek: The Next Generation wrapped 17 years ago, you may be struggling to recognize thirty-something Wil Wheaton as the simpering Mary Sue character Wesley Crusher. Wheaton also portrayed Gordie LaChance in the 1986 coming-of-age tearjerker Stand By Me. Still not ringing a bell? He also did two independent films: The Good Things, and Jane White is Sick and Twisted. Oh yeah, he's that guy!

Summer Glau

If you're not a hardcore Joss Whedon fanatic, you may not instantly recognize her as River Tam from Firefly and Serenity. She also appeared on Terminator: The Sarah Connor Chronicles as the cyborg terminator Cameron. She plays herself on The Big Bang Theory, but was criticized for being too machine-like. That's called a nod, folks. Winking is too obvious.

Laurie Metcalf

Sheldon's religious mother looks so familiar. She portrayed Aunt Jackie, Roseanne's sister, on Roseanne. She has also lent her voice to all three Toy Story movies. She has won three Emmys and been nominated for a SAG Award, a Tony, and a Golden Globe in addition to making plenty of cameos in award-winning series such as Grey's Anatomy, Monk, Desperate Housewives, and Frasier.

Christine Baranski

Leonard's mom is played by Juliard-trained actress Christine Baranski. Her resume starts at 1980 and is jam-packed every year since, but you probably remember her most for her sexy, all-business portrayal of Katherine Archer in The Birdcage opposite Robin Williams. She also depicted Mary Sunshine in Chicago.

While these actors and actresses gracing The Big Bang Theory are all working quite often, their roles may not immediately jump out at you. With the show being confirmed for the next three seasons, I'm looking forward to more fun, off-beat cameos by unexpected performers. When are they going to call Weird Al?

Matthew Warren works for the geek-centric t-shirt site Gump Tees which feature The Big Bang Theory Shirts among other nerdy themes.