What PC PCI cards can be used in a Macintosh?

I know that I can use certain PC Ethernet cards in a PowerMac, and use them in Classic Mac OS -- depending on driver availability. I know that I can use just about any PCI ethernet card in existence on a PowerMac running Linux.

I know that I can plug PC USB and Firewire cards in my PowerMac and use them with the proper drivers.

What other types of PCI cards can I take from the PC world and use in a PowerMac? Will SCSI or ATA cards from the PC side work in a PowerMac?

I know that some video cards from the PC world can be flashed to work on a Mac. What other kinds of PC goodness can be used in a PCI PowerMac?