I don't see why Death is on there at all (I'm assuming you mean the Death Metal act...), I'd say Morbid Angel is FAR more important to death metal than Death is (Controversial opinions up here!). After all, Covenant is the best selling Death Metal album of all time iirc. But even then, as much as I love Death Metal, its by and far and underground genre of music and probably can be passed over.
I'd agree on NWOBHM being included. I'd say Judas Priest and Iron Maiden deserve some mention for what they did for it. As well as Dio's solo career.
The big four of the British Invasion definitely need to be mentioned, even if I don't really care for them at all.
If you're going to include Prog, then King Crimson definitely needs some love, as well as Genesis and Rush. Maybe ELP/Jethro Tull, maybe.
I think there would have to be more than a top 10 though, that's far too constricting.