Imho, anything that will fit!
What's your budget?
You can go with some
Ample Audio (very clear... I replaced my Dad's rear speakers with them; he likes them a lot.) to competition level speakers like
Rainbows. Since I am more sound quality-oriented (which seems to explain you, too), MB Quarts, Focal and CDT Audio should be some considerations. (Infinity is also a nice alternative.) If you do not wish to amplify your speakers, I would suggest Audiobahn because of their relatively high sensitivity.
Don't forget to listen to the speakers that you are considering!