See my FAQs*:
http://www.macmaps.com/macosxnative.html
http://www.macmaps.com/macgamepages.html
As you'll see any old games that require Classic essentially require an operating system that hasn't been updated since 2001.
Booting into Mac OS 9 gives you full driver support of Classic applications.
Using Classic only gives you partial support of Classic applications.
10.5 eliminates Classic, but still supports booting into 9 if you have a pre-2003 Mac (the 1 to 1.25 Ghz MDD G4 with no Firewire 800 which was available in 2003 and later new was really a pre-2003 Mac) that is 867 Mhz or faster.
PowerPC Macs released 2003 and later could only use Classic when booting into 10.4.11 or earlier. A Firewire hard drive or second partition allows you to have 10.4.11 or earlier simultaneously installed with 10.5 on the same Mac allowing you to use those older software titles.
2006 and later Macs use the Intel CPU, and they can't boot into 9, nor can they use Classic.
You can find used and refurbished Macs*:
http://www.macmaps.com/usedrefurbished.html
which will allow you to run older games if they haven't been upgraded to current compatibility.
The irony is, 2006 and later Macs have better hardware support for all Windows and Linux operating systems than older Macs, thus allowing you to run in virtualization Windows or Linux at native speeds, and giving you full compatibility with Windows and Linux games which was only possible through emulation before.
- * Links to my pages may give me compensation.