I'll add another post in favor of Gygaxes. If we're going to measure this even pseudoscientifically, may as well stick to reasonably scientific conventions. Besides, the convenient abbreviation (for writing out the unit in long texts full of unit references) would likely be gx, which is unlikely to be confused with any other unit abbreviation I'm aware of. The TSR is effectively its own abbreviation- it's one letter longer and really just doesn't look right in lowercase (tsrs vs. TSRs).
But, one thing that occurred to me reading this is, if we get a way to measure game complexity, this might lead to an objective measure of DM skill; as in, "Hey, he ran that 10-gygax monster without breaking a sweat, and crushed the PCs with it besides! I could never do that, the best I can do is a 5-gygax one on a good day. With lots of Mountain Dew."
This, in turn, would lead to a real DM rating system, like we see in Knights of the Dinner Table for Hackmaster GMs. Being accredited "level X" means you can successfully run Y-gygax monsters without forgetting anything or needing to look it up. Would this be a good thing, or a bad thing, I wonder? Probably a bit of both, but how?
EDIT: After re-reading the thread about "Preserving the Sweet Spot- a Rebuttal," I have to think that this would be more good than bad. From the posts being made on that thread, it looks to me like the majority of people are intimidated away from high-level play because of the extreme complexity of it- but the fact of the matter is, what is horrifically difficult for some people to keep in their heads or figure out is a cakewalk to others. Having a semi-objective measure of game complexity could change the vitriol associated with all these arguments about the game "breaking down" at high levels to something more positive. We'd start seeing threads on "Is it possible to run a high-level, low-gygax game?" or "Anybody running 10gx games in the Dallas-Ft. Worth area?" instead of "Let's get rid of the higher levels" or other similar notions.
It might also help alleviate DM frustration in that those who find themselves unable to run super-complex games have a better idea of where to draw the line, so that they can either work on improving, or know where to stop, instead of trying to bite off more than they can chew multiple times and/or getting burnt out on GMing. Game quality in general should improve as a result, yes?