I use my 6 1/2 X 24" and my 12 1/2" square rulers the most. I use a 6 1/2" square that I use for smaller pieces.
I have all sizes of rulers. I'm a gadget person. I buy lots of rulers and gadgets.
I have a 20 1/2" square ruler that I seldom use but, when I need it, I'm glad I have it.

I have various sized square up rulers, I like to use the one that is closest to the block size... It feels more comfortable to me too :D:D:D

I have a LOT of rulers. I want the size that is closest to the size of my block or piece of fabric.

I do prefer the Omnigrid rulers because of the dots and the see-thru areas as opposed to the ones with the fatter solid lines.

8.5 x 24 - use it all the time, had to buy a second because the first wore out.

I have a 9.5 x 9.5 that would work well for squaring up 8.5" blocks. I think I'll buy a 12.5 x 12.5 the next time they go on sale or I have a coupon to use.

My favorites are the Quilter's Rule brand..with the nubbies on the back to grip the fabric. Any size...as long as they have the nubbies. =)

I have the 6 1/2" ruler....have the marks about worn off. Wish they had 8 1/2" ruler.

I use so many depending on the project. But when I decided to just cut up fabric I used the 6 1/2 square and wore off all the markings.

i use june taylors square up rulers, they have the 1/4" all the way around the ruler in a darker color. i think i like this type best. you can get the little snadpaper dots at any hardware shop to put on the back for slippage.

i love my creative grid rulers..i now own 3 of them.

My favorites are the ones that I have in my hand at any given time, but the ones I use the most are my 6 1/2 x 12" and my 6 1/2" x 6 1/2". I prefer the EZ Quilting rulers by Sharon Hultgren, uncluttered, easy to see, and easy to use.