I've always thought it would be better to rank all games on one piece of hardware (ok maybe a few, AMD, Intel, ect). And not emphasize the frame rate, but how they rate compared to each other.
Why? So when you buy a new piece of hardware, you can run down the lost and move up / down the list until you find the slowest games you can run at near / full fps... And only add those to your cab.
This way you don't have to look around and try them all... or worse yet... run a game for the first time when others are over... and make your cab seem broken.
Not bad idea for comparing
general game play.
People won't be satisfied though, since different games like different hardware err... differently.
You'd need a list for at least a64, p4, & core2 CPUs, and possibly for core, pm, p3, semperon, & athlon(32); game P(sx) might run slower than game Q on cpu A(md), but faster on cpu I(ntel).
Add that game X might be okay at 90% fps while game Y sucks at steady 95% fps.
Or game Z averages 97% fps but goes to 50% at some key point vs that game W that never goes below 90% averaging 95%.
And newer versions of mame effect different games more than others (such as adding dynamic recompilation, or better emulation) possibly moving games up or down the list.
And there are 6000+ games (3000+ parents); by the time you run them all, the next major version will be out.

Not that that game relativity lists are a bad idea; they would make it easier for people with slightly different hardware than tested to dial in on which boarderline games to test, and which are hopeless. I just don't think they'll be any easier to keep up to date.
Nope... I tried Pac-Man and Soul Edge really quicky and got exactly the same frame rates with HyperThreading turned off.
Chris, did you enable mame's multithread option (-mt) with hyperthread on? Looking at the
mame32 benches, John noticed a difference. Compare the d3d@3.6, d3d/MT@3.6, and nv/ns@3.6 columns. (-mt = multithread, nv/ns = no video, no sound). He used a core 2 duo, though.