To make things even easier
for you, I would start with Mirror.
I think Mirror is more diverse and - dare I say it - more prog. Although Numb has got some stellar songs, after a while the album started to sound a bit 'samey' to me. I think this is mainly because there are no keyboards present on this album.
On Mirror, there are actually three different 'types' of songs. There are the typical prog-songs, sung by Paul Wrightson, there are a few rockier tunes sung by John Mitchell, and there are a few instrumental songs as well. Because of this, the album doesn't sound quite as coherent as Numb, but it's great nevertheless and it's the one I would recommend to someone who isn't familiar with Blind Ego.
I hope this helps.