Hmm, for me, 60hz on a CRT absolutely tears my eyes up, and gives me a headache. 75hz is OK, but not best. 85hz is excellent, with 90hz+ being as far as I can tell, a 100% stable picture for my eyes. there is an ever so slight flicker that's more bothersome then anything at 85hz w/my eyes, but that's just me, I guess. never actually noticed it till I cranked the refresh up to 100hz...
If you have an LCD, just run at 60hz...it might extend it's life, and you won't notice a touch of difference picture-wise(maybe even a little sharper than higher refreshes)