I loved it for the first 3 seasons. Then they turn it into the usual couples sitcom and lost all its appeal.
I liked the dynamic of having all main characters "fail" in life. Penny failed as an actress, Leonard failed in dating Penny, Howard failed as a playboy, Raj failed talking to women and Sheldon failed at social integration. They were all adorable losers that had fun while losing. For me it kinda was giving a lot of hope, like you don't have to succeed in life to have a good time.
Then they made them all winners, they all became rich, and achieve all their goals. And all hope was lost. And the message was "you better succeed in life" which was depressing.
I could do it once. When the "lesser evil" decides their whole strategy is being the lesser evil and blackmail me with "if you don't vote us the big evil will come" then I grow tired and issue a big fuck you to the "lesser evil".