this is going to be one of those opinionated threads. here, i'll start:
i like hutchinson pythons 2.00
they are very light, but so am i.
from what i understand, it is sometimes hard to compare widths across brands. one brand's 2.10 might be another's 2.20, or maybe i am wrong. i wouldn't get so hung up on the actual width. maybe try to choose based on terrain, riding style, etc.
it's funny how people can be anal about the tires so much. fact is, a good rider will compensate and won't even matter. i have been racing in dry terrain with almost bald tires and then i listen to people riding with me b!tching about their tires not cornering well
(that wasn't to imply i am a good rider)
i'd rather have a light tire that didn't "corner" as well