A primary focus throughout most of the season is Leonard (Johnny Galecki) and Penny's (Kaley Cuoco) developing relationship. After two seasons of Leonard pining over Penny, the two finally hook up and give dating a try. It's a logical step and, thankfully, doesn't devolve the show's premise. They're together, but it's only a "big deal" in a handful of episodes. Usually it's something in the background.
Though Penny and Leonard avoid most common sitcom relationship plots, they never feel completely comfortable as a couple. There's very little chemistry between the two. It never feels forced, but it's uncomfortable enough to make you question why they're together. This is sort of the point, but there's really no reason to root for them either. The only really good thing to come out of the pairing is a great role-reversal where Leonard has to step into Penny's world with her friends.
Season Three continues what was easily one of the best trends to come out of Season Two - Sheldon (Jim Parsons) and Penny's friendship. Somehow or another, the two have figured out how to get along, setting up some of the show's best moments. While Leonard and Penny lack a likeable chemistry, Penny and Sheldon make for a great comedic duo.
As always, Sheldon steals nearly every scene he's in. Jim Parsons is great in the role and his comedic talent gets a chance to shine in numerous episodes. We get to see how Leonard and Sheldon's friendship started (as well as why the elevator is broken) as well as his encounters with Stan Lee and hated-rival, Wil Wheaton. The Sheldon-Wheaton rivalry packs just as much punch as Sheldon's relationship with Penny.
The Complete Third Season also tosses in a few extras. There's a mostly forgettable set tour with Simon Helberg and Kunal Nayyar, as well as a short gag reel. The best of the bunch is a cast discussion moderated by a box of fortune cookies. Yes, you read that right.
A Blu-ray purchase over the DVD isn't necessary, but worth it if you're a fan and want the best possible version.
Season Three was a great run for The Big Bang Theory. After two years of being a show that was really only funny to geeks, it blossomed into something more. The geek humor is still front and center, but somehow the awkwardly motley crew grew into a great ensemble case. Sure, some of the humor will still fly over "non-geek" heads, but even if you don't get every joke, there's still a lot here.