Ok....Some Specs:

MSI K8N Neo4-F nForce4 Socket 939 ATX Motherboard
AMD Athlon 64 3400+ Single core
256MB Nvidia 7300 GT
1 Gig RAM
200 Gig IDE hard drive
I have a PCI network card because the built in one didn't work with Leopard.

My BIOS settings are nothing special. I don't remember changing anything. Pretty sure it's just however it came out of the box.
Hard drive and DVD ROM are both IDE. Purposefully bought IDE because of issues at the time with SATA. (10.4.8)

I did kind of an interesting install because there were no AMD install DVDs when I did it. (Right after the very first ToH DVD came out.)
I had been running Tiger for several months. I downloaded the ToH DVD and mounted it read/write. Ran Marvin's on it. Edited the video kexts with my device id and injected nvInject so that it would boot up. Unmounted it and burned it.
I backed up all my data (since this is my main workstation), partitioned the drive with the Jas 10.4.8 AMD/Intel DVD. First partition a large partition for Leo. Second partition a very small partition for Tiger. Installed Tiger on the small partition. Booted into it and created account, downloaded Startupfile tool just in case, etc....
Booted the modified ToH DVD and installed Leopard on the large partition. Then nothing would boot so I had to boot up with the DVD again and use Startupfile so it would boot.
Booted into Tiger and ran Marvin's on the newly installed Leopard partition. Inserted NVInject. Modified the needed kexts for video card.
Booted right into Leopard. :-))
I have since installed EFI v8. (I installed EFI v5 first and have since updated to v8.) I have installed all updates that have came out. (Careful to remove AppleIntelCPUPowerManagement.kext that came with 10.5.2)

I'm using Netkas' AppleSMBIos.kext.
I'm using the IONetworkingFamily.kext that is in the Time Machine fix link in the topic of the Leopard channel on irc.osx86.hu
I'm running the 9.2.2 kernel and System.kext posted somewhere on this board....

Hmmm...What else..........Those are the only kexts I've replaced since install back in....I think it was November. Some got replaced with updates along the way, obviously, but I don't remember what they were. I didn't worry about them. Just let the updates install them. I always run Marvin's after major updates like the 10.5.2...etc. (From Tiger) Plus I run it on the /Applications directory and /Library directory after some installs. (I know Toast has some CPUIDs that need patched..) There are some others too.....In these cases, I just run it from within Leopard. Doesn't hurt.

That's about it. All I can think of at the moment....

Tim