Overall, I'd give it around 8/10, however comedy wise, I'd give it a 7/10. I think the main appeal of the show and why it's so popular is that it's very easy to follow unlike the less popular but more meta comedy series like Community.
What are your thoughts?
I'd rate it around an 8.5 out of 10. I think the character development is great - we know so much about Sheldon, Leonard, Raj, Howard, Penny, Amy and Bernadette that I think they can almost feel like people we know in real life, sometimes. That to me is how I identify the worth and connection I have to a show a lot of the time.
I love that the show is factual in the scientific theory it presents - it's always nice to know the scriptwriters are doing their research.
The only complaints I really have about the show is that lately some of it feels like it's stagnating a bit at times - but that can happen when a show has already been around for such a long while. I'm excited to see some more changes in the characters lives that might shake things up a bit.