Glycemic indexes

What reference food based glycemic index are you people using? white bread or glucose solution and what values are you considering (ie less than what) to be low GI

i use the index where white bread is 100. it was the first one got my hands on, so i guess i am just used to using it. i don’t think one is better than the other as long as you know what scale is being used in discussion to keep the indexes relative.