The Cricut is more oriented to scrapbooking. These can do a lot of custom shapes, but just one at a time.
The Accuquilt (Go! and Studio) are more oriented to quilting. These are die cutters that allow you to cut 4 to 10 layers of fabric at a time in the shape you have selected.
There is also an Alto Quiltcut which is basically a sophisticated ruler setup for cutting with a rotary cutter.
I have an Accuquilt Go! and really like it for certain things -- especially triangles, because with the corners nipped they are very easy to cut and sew accurately. Also like the strip cutters, although I can probably do these at least as fast with a rotary cutter and Shape Cutter ruler.