Holographic Universe it´s probably their best one, with Pitch Black Progress coming close. Anyway, I think The Unseen Empire it´s awesome. The songs are much more simple, some of them have some 80´s hard rock feeling, lacks some prog vibe from older albuns but the songs are catchy and very well written.
The only weak album for me it´s Dark Matter Dimensions, it sounds quite uninspiring but it has one of their best songs ever, A Parenthesis In Eternity. The rest is quite forgettable.
This song has one of the most cheesy chorus ever, remind me those glam rock bands from 80´s but in really bad way.