I like the EK Success Curvy Cutter system, which has several other shape templates available as well, such as ovals and rounded squares. It cuts in twelve different sizes per template, although not quite as large as you're looking for.
I'm sure someone will tell you to just get a Cricut, but I get the impression you're looking for a lower-budget tool, which is also fine.
I use the EK Success- Cutter Bee. Maybe it's just me, but it takes a certain knack to get it right everytime. I haven't made circles in a while, but I just got SCAL2 for my Expression-- I'm pretty sure they'll be circles for that. I'm hoping to make bigger ones with it.
I also love raiding the kitchen for tools, as they said you can get some of the best sizes for a great price! Whenever we lose a lid or the bottom for a piece of tupperware the lone piece gets carried away to my scrap room. I also have a scratched CD I use for medium and small circles. I also hunted down a roughly 10.5" plate at the thrift store that now has a permanent home in my scrap room.
I love my Fiskars Ultra Shape Express, with the large template circles. The advantage is that you lay the circles right over the paper. What you see is what you cut. No guessing! The trick is to hold the USX like a computer mouse, and make sure that the template is right side up (the Fiskars name should be face-up). Easy peasy.
I bought one of those Compasses like you use in school to draw a circle. One side is the pencil and one is a pointed metal thingy that you place on the paper and then turn the pencil around in a circle. (I tend to go for inexpensive solutions.)
I must admit that a Cricut Expression is on my wish list though.
I just bought the making memories circle cutter. since this is my first circle cutter, I have nothing else to compare it too. It works fine for me..does the job. I have punches to cut circles 1.0" - 1.50"
I trace around anything I have to get that just right size circle, and I cut them out with my cuticle scissors. The curved edge works great. I have other cutting things to work with, but I always go back to them!
I use the Creative Memories cutter system. It has 3 circle guides. The circle guides have a groove in it and the actual cutter piece fits in it. The cutter pieces are 3 different sizes so each guide allows you to cut 3 differnt size circles. It works great and you have lots of options.
If you want to cut a picture in a circle you pick the size. If you pick a smaller circle you can cut bigger ones from the same guide and make matts for your picture.
The best one is the Fiskars Shape Cutters, I use all the templates that are available, I find them much easier then the CM if your not sure what I mean then have a look http://shapecuttersforscr apbooking.blogspot.com/ I think it may show you CM's as well?
I use my cuticle scissors, I have used the same pair for several years. The curve helps with my cutting small pieces in my paper piecing and works for circles too. So I just find something in my home to trace around that's the size I want and cut it out. i save the money for some other scrapbook item.
I love my Creative Memories circle cutters...they're awesome! I now have the Cricut Expression but will still use my CM cutter. I have the George & Basic Shapes cartridge that I bought from an individual and it is great for basic stuff!
Go pay a visit to your kitchen cupboards to find many sized circle templates. The answer to making them is to glide your scissors through the pencil line, and move the paper instead of the scissors so you don't get a "chunky" edge as you cut. Or, if the "chunky" look is what you are looking for try tearing the shape along the pencil line.