Giants for 2006 TCRs are XS, S, M, M/L, L and XL. You guys should probably take a gander at their site before you go around saying that they have very limited sizing options. 6 sizes will do the trick for just about anyone.

So thats like a 47 (i know a girl who rides an XS, and she's tiny), 50 (I ride a 50 and a Small), 52/3, 55, 57, 59/60ish. Just my personal guesses. Thats pretty near what most other companies offer. Trek, arguably one of the best known brands in the US, "only" offers 7 sizes.