Wow, sorry, I somehow hopped over that part when reading it the first time.
In any case I'd say your next best best is Into the Electric Castle and either of the Star One albums.
I agree. Into The Electric Castle
was his breakthrough album, and it solidified his presence in modern prog history, IMO. After that, you could venture on to the 2-part album Universal Migrator
, whose two parts are titled The Dream Sequencer
(a more moody, Floydian spacey/jammy album) and Flight Of The Migrator
(a more balls-to-the-wall prog-metal beast).
If you can get through those albums, then I'd suggest getting 01011001
and his first album The Final Experiment
. Both are pretty good, but the latter a bit same-y to me, while the former is a bit dated-sounding, but it helps complete the over-arching concept and story behind the Ayreon albums.