I would go along with Camel. Excellent music thats easy to absorb and enjoy on your first listens - not like Yes for example, where you sometimes have to concentrate hard to hear if there is a melody at all.
I would also reccomend Red by King Crimson. A lot of KC's material is NOT a good starting point, as it is quite out there, but Red strikes a good balance between hard rock, and prog subtlety. Its one of those 'classic' prog albums of the 70's, but one like no other. and thats from someone who is not really a big KC fan.
I see you have Genesis and Floyd covered, thats good! You may want to try some ELP, Tarkus is a good album; very dramatic with a classic prog feel. But above all, for someone young like yourself I would strongly reccomend you investigate Rush. Try the albums 'Hemispheres' from 1978 and 'Moving Pictures' from 1981.