I use my 12 1/2 square the most; But I sure am glad I have the 16 1/2 for the several times I needed it, comes in really handy for the 14 inch blocks.

10 1/2 is my largest, but I want 16 1/2, too.

I have a 16, and could not sew without it

I have a 20 1/2" square...don't use it very oftern though. I prefer the 12 1/2".

I have a 20 1/2. Just got it a couple months ago. Dont use it as much as my smaller ones but it sure is nice when you want it have it. Got it 60% off at Joann's

12 1/2" :).
Marcia

I have 1 1/4 to 12 1/2 square rulers,,I'm not sure what/how I'd store anything larger...though I'd like 15 1/2, 16 1/2 and 18 1/2

I have lots, from 1 1/2 inch to 20 inch, use them all. At JoAnns the groups with 3 or 4 different sizes for a resonable price when you use the coupons!

Mine is a Creative Grid non-slip 20 1/2 in ruler. Not been used as yet..but non the less is there if I need it.

16.5, don't use it as much as my 12.5 but comes in handy now and then. Got it at a yard sale for 8 dollars. One of our guild members passed away and her daughter had all her quilting supplies in a yard sale. Most of the items were over priced so when I saw 8 on this, I grabbed it quickly. I'm sure they didn't know the actual cost or it would have been much more.