I have now watched about 5 episodes of The Big Bang Theory, and while the show is well written with witty dialogue that appeals to the geek inside me, the acting doesn't exactly "float my boat". Darlene's boyfriend from Roseanne over-acts his character and is not worth watching, his neurotic roommate gets more annoying each time I watch the show, and the girl from 8 Simple Rules is pleasant to look at but is not a skilled actress. I think the writing is fantastic, but the acting is mostly just annoying.
Right now my favourite sitcom is My Name Is Earl. Big Bang Theory has better writing, but for my money Jason Lee has more acting talent in his pinkie finger than the entire cast of Big Bang. If Jason Lee does not win the next award for best lead in a comedy series, something is wrong with the voting process for that award.