Just curious... I have a PowerMac G5, and all the following games are ready to play on it. All are Full Installations where applicable. For Myst III: Exile I have to turn off one of my two CPUs.

Myst Masterpiece - (under Classic using QT 6.0.3; no CD necessary)
Riven - (under Classic using QT 6.0.3; no CDs)
Myst III: Exile - (under Mac OS X using QT 7.1.6; no CDs)
Myst IV: Revelation - (same as above except DVD required)
Myst V: End of Ages - (same as above except DVD required)

Currently I have:

Myst Masterpiece
Riven - (Just started playing this one today)
Myst III: Exile - (Playing this one next after Riven)
Myst URU - Complete Chronicals - (Completed and the game that got me hooked on the rest of the series)
Myst IV: Revelation - (Stuck at the Spider chair)
Myst V: End of Ages - (Completed 2 of the 3 endings - hope that's not a spoiler)

Unfortunately I cannot play Uru on my Mac; have to use wifey's PC. Uru is not ported to the PowerMac, although it can be played (I understand) on an Intel Mac using Parallels. And I am having occasional random freezing on Myst V... an annoyance.