I posty same thingy as in another recent thread.
I would recommend checking out the Labyrinth stuff in this order:
RTHD II (seems to be a great entry point, and an incredible album to boot)
RTHD
Labyrinth (close/tie between where this is and RTHD is)
No Limits
Freeman
6 Days to Nowhere
Sons of Thunder
Don't listen to anyone who forbids you from anything besides RTHD, for they know naught the goodness of the mighty prog-power contained otherwise.
Heck, a couple of them have less filler than the original RTHD..
and to add on to that, a few notes about each: The self titled is one of the greatest examples I can think of concerning pure power metal and progressive ideas, e.g. 'progpower', as a record. Everything just WORKS. The band chemistry and creativity is dazzling, but the sound doesn't suit the nowadays metal crowd who can't decide if they want a band to be TEH 100% original, or sound exactly like another band..a voice carrying neither pretention is oft-greeted with confusion. 'No Limits' is along the same lines, but slightly less experimental, and a little darker, and has a very clear-throated Fabio Lione on vocals. 'Freeman' is diverse in a good way, scaling down a lot of faster, evenly spaced sounding songs for more of a down to earth feel, this record really shows the band trying their hand at songwriting which, while much simpler, is trying to do something different with a shorter range, and it mostly works very well, though in my opinion the last few songs are some filler. '6 Days' and 'Sons' are very easily the weakest though there are some must-hear songs between them, e.g. 'Lost', 'Kathryn'.. band needs way more credit than just 'they made a great album and a good sequel album'.