HIMYM sure has it's moments but it suffers from the conventions of popular American sitcoms (predictible jokes, shallow stereotypical characters with bland ideals etc.). If it's any consolation, it's far better than Two and a Half Men and The Big Bang Theory.
There's very few decent sitcoms left on television. HBO's Curb Your Enthusiasm has it's fair share of moments but it's far from a traditional sit-com while a number of shows have been found guilty of phoning it in (Hello Scrubs!).
I do hear good things about It's Always Sunny In Philadelphia, 30 Rock and Better Off Ted. Unfortunately most of those shows require chronological viewing.
As for classic sit-coms, I still find Frasier to be one of the better sitcoms of the 90's. The Nanny wasn't THAT bad: I thought the Butler was a classic sitcom character. Everybody Loves Raymond, while painful did have it's share of decent moments. Unfortunately, the show was too formulatic and had you seen one episode, you'd seen them all. Becker doesn't need any defending - it was solid.