You should just pick them yourself, but here are some sugestions:

Castle:
Stardust memorys by Jester. (stardust.mod)
Sharded Dig by Alex B.(Digsh.s3m)
Regular castle music.(castle.2b)

Diamondus:
JJ1 Diamondus song.(song3.s3m/diamondus.s3m)
Phantasmagoria by 4-mat.(phnantasma.mod)
Regular Diamondus music.(Diamond.j2b)

Tubelectric:
Nowhere to run by Alchemist.(alc_run.xm)
The genesis factor by Sorath.(Sor-genesis.it)
JJ1 Tubelectric music.(tubelectric.s3m/song0.s3m)
JJ2TUbelectric remix.(die.s3m)
Regular tubelectric music.(tubelec.j2b)

Egypt:
Egyptian magician by Morning w00d.(egyptian.mod)
ZARATHUSTRA by DRAX.(Zarathus.xm)