Each are default if not listed here.
GateA20 fast
VideoBiosShadow disabled
Advanced section.
SystemBioscacheable disabled.
VideoRAMcacheable disabled
Dram section (depends on memory I run crucial and haven't had a problem)
System performance Turbo
DRAM Timing Manual
Cycle length 2
Bank interleave 4x
AGP aperature 128Mb
AGP mode 4x
AGP fastwrite DISABLED (radeons don't use this)
The memory timings may not work with your memory, you may also have to increase the cycle length to 2.5 if you are O/c or have a no-name memory.
I usually change some other stuff, but that's the basics, as I read up on something I can understand what it does and change it.