I'm gonna try to do this one without reading anyone else's for influences
The Enemy Inside
Lost Not Forgotten
Repentance (without the 3 minute long "aaaah" section that makes the song way too long)
Surrender To Reason
A Nightmare to Remember
Far From Heaven
Octavarium
Trying to keep it balanced while trying to represent all albums at least a bit (I know Repentance might not seem the best representation for SC but it does work well in this context). It's 75 minutes long, which is a bit long but there's a ANTR and 8VM in there, so nothing less could be expected. It still is 7 songs long, which is fairly good.
OTBOA, BITS, FFH, BAI, LNF, TITL, Outcry, BTS, FAS, TEI, TLG, EM, TBP, BTV, STR, AFTR, IT, TCOT, Wither, ANTR, TBOT, TSF, ITPOE, Repentance, TDEN, TMoLS, 8VM, TROAE, TW
If I had to do a two CDs version it would be like this:
This one looks weird because of how many Th's there are at the beginning of the song names, but oh well
Surrender To Reason
Bridges in the Sky
The Enemy Inside
This is the Life
The Dark Eternal Night
Lost Not Forgotten
The Bigger Picture
The Root of All Evil
The Looking Glass
Wither
On the Backs of Angels
Outcry
Illumination Theory