I love this series. The funniest series in a long time. I especially love the interactions between Sheldon and Penny. I still believe, that if the series lasts long enough, these two should finally end up together.
One of my favorite moments in season 2:
And I don't see what Penny sees in Leonard. He is just too whiny. Though I haven't seen any episodes from season 3, so I do not know how this develops. But everytime I see Sheldon and Penny interact, I see moments where she seems to see past his eccentricities. And the fact that Sheldon often seeks out Penny's advice at least shows, that he has come to like her.And also: Rachel and Joey had more sparks between them than Ross and Rachel towards the end of the series.
I do think Penny and Sheldon have wonderful interactions, but I don't see them as a couple. Sheldon has accepted her as a friend..but I don't think he'd go further. He doesn't even talk about liking women. The closest he's really come is when he sort of stole Raj's date..and even then he had no clue what he'd done wrong.