It really depends on the type of quilting you do. The computerized ones, like the Cricut & Silhouette are great for applique. You can basically cut just about any shape you want and there are no dies to purchase and store, however, depending on the brand, you may have to purchase cartridges. You can generally only cut one layer at a time with these, and the blade will need replacing periodically.
With a machine that uses a die board, like the GO, you can cut many layers at a time, however, you do have to purchase a die for each one. If you are cutting a lot of shapes that you are going to piece with like squares, strips, triangles etc. Then the GO is the way to go.
There are lots of threads on this board regarding this question. You can do a search and read them. Here's a link to a site with lots of comparison info:
http://heartofwisdom.com/heartathome...ting-machines/