The one I like best is the Martelli Ergonomic Cutter, it's easier on the hands/arms and I have better control on my cutting. I have the Gingher, Olfa & Fiskars in all sizes and I used then for different projects. You will need a larger one to cut several layers, a med size for up to 4 layers and a small one on curves. When cutting several layers, I find the fabric wants to move, so either iron it together before cutting or use temp. fabric spray. This will help. Also, get a fillet glove(for fish) at the sporting or hardware store. I have also seen them at some quilt shops under a different name. That will save stitches in your finger.

I used to use an Olfa 60 mm, especially if I'm standing and cutting many layers - the one with the squeeze handle which makes the blade come out and retracts as soon as you let go. But when I saw someone at my favorite quilt shop cutting with a Martelli, I knew I had to get one. Now I use that most of the time, especially when paper piecing, since I'm sitting then, it's easier on my arm. If you want to cut many layers, you just need to use a larger diameter blade, no matter what brand. I always wait to buy any rotary cutting tools when the store has them on sale or I use a coupon, then the cost isn't such a shock.

I love those Olfa's that have the retracting blade. I was always leaving my cutter "open". Never had a accident, but I knew one was waiting to happen. I have now invested in the retractable ones, using my discount coupon's from Joann's and I LOVE them and so do my worried quilting friends!

I have always used Fiskars. I have two and they are both this brand. Very happy.

I bought the Martelli spring 2009, - then in June developed carpal tunnel that progressed extremely quickly to being operable. Amazingly, I was still cutting with this right up to the night prior to surgery, - could not use any of my other brands, - could not use a knife to prepare meals, could not hold a pen to write. My husband made the comment that I needed to rotary cut my vegetables. Within 2 wks of surgery, I was again using my Martelli. I'm sure I'll be using others at some time in the future, but for now, I am so glad for that impulsive buy. I love it.

Olfa for me! And I've worked with quite a few.

I have a Dritz 60mm that can be adjusted to light or heavy cuts and the shield is retractable. It is also equipped to be locked when not in use. I also have the Olfa 45mm and a smaller one yet just for trimming dog ears (on HSTs!), and I recently purchased an ergonomic Fiskars 45mm. I can't say which one I like best, as each has a quality or qualities I like.

I like the new rotary cutter that goes lefty or righty Olfa it is more costly but it would allow you to cut with either hand.

Dritz has a rotary cutter that sells at JoAnn that I have truly appreciated. It has a setting for single layer fabric, or multiple layer fabric, and a lock blade down. When the lock is removed and put on one of the settings, the blade is not exposed. When you place the cutter on the fabric and press to cut, the blade is then exposed. It is a dark Royal blue in color. I just wish I could find it in the smaller blade size, as the cost of the blades go up with the size of the blade. I use the 45mm.
Marsha

I use Olfa.