A few years ago when I sewed my first big quilt, the lady who taught the class suggested 2 1/4, using a 1/4 seam. She ventured to say she hand sewed it to finish it and liked a thin binding, I like the binding cut from 2 1/2 inch, I am tempted sometime to dry a bit wider.

I use 2.5 inches, for me it seems to work the best and goes over your quarter seam very easily and tightly... and it looks good...
Ladybug

I have always used 2 1/2, but it could go narrower. I wouldn't go less than 2 inches though. That's just me.

2-2 1/2 depending on the quilt and the width you like.

Ditto!

I use 2 1/2 inches for double fold binding.

If you go a bit wider on the binding, you'll have to take a "bigger" chunk on the first seam when you sew it to the front of the quilt, like 3/8" or the front will be narrower than the back when you fold the binding to the back to sew it on. If you are thinking of ever having the quilt judged, the judges want the front and back to be the same and the fold of the binding to have the sandwich part filled to the crease.