"Dungeon Siege" works surprisingly well under Crossover Mac 7.0. Has only the following issues that I can see:
a: Installs fine, but you need a No-CD patch to play.
b: The startup videos you see promoting the developers are all distorted and partially clipped.
c: The in-game cursor has a square artifact surrounding it that appears to be some sort of mirroring of the surrounding game environment. Works otherwise.
Aside from these 3 issues, it plays downright perfectly! See screenshots taken by myself.