As far as cute goes, I would direct you to perhaps the most tightly-scripted comedy anime ever created: Galaxy Angel. It's not for everyone, but it's iconic for lots of different reasons, most notably the jokes. The other series I mentioned, K-On, Hidamari Sketch, Potemayo, Ichigo Mashimaro are all lighthearted slice-of-life comedies, though Hidamari has a very sedated pace As far as cute goes, I would direct you to perhaps the most tightly-scripted comedy anime ever created: Galaxy Angel. It's not for everyone, but it's iconic for lots of different reasons, most notably the jokes. The other series I mentioned, K-On, Hidamari Sketch, Potemayo, Ichigo Mashimaro are all lighthearted slice-of-life comedies, though Hidamari has a very sedated pace (but unique visual style). For a much more straight comedy, I would also recommend Seto no Hanayome, which I had more fun watching than any comedy in recent memory. Most cute series tend to be slice-of-life stuff, and are usually slower-paced, but fun to watch. Kamichu is another fantastic series in that vein, with a fantastic studio behind it.
Jimmeh mentioned Azumanga Daioh, which is a now-legendary comedy, which I still haven't been able to sit through, personally. The manga is unparalleled, though.
Also, try watching the first episodes of some of the stuff I mentioned in my first post. This season is WAY above the usual average with regards to good series. Panty & Stocking, Kuragehime, and The World God Only Knows are all great shows, as are the others in my list (though you may not appreciate SRW for all the giant robots and cheesiness).
It's incredible. Very meta.