"Futari ecchi" is the funniest anime i have seen, but i dont think it will belong to the comedy category, i would say it belongs to ecchi, it is full of ecchi, but still its worth saying it is comedy. i bet u all will love it
I agree Nodame Cantabile and Ouran Host Club is very funny. I also like Yamato Nadeshiko Shichi Henge (Perfect Girl Evolution or Wallflower). Currently watching Bamboo Blade which is very funny too.