I just went throught this same process and it totally depends on how much you are willing to spend and whether or not you plan on quilting your own quilts or sending them out to be done - as well as the size of the quilts you plan on making!
I piece with a Kenmore and have quilted with it too, but have upgraded to the Janome 1600P for quilting.
Great to Excellent brands include Elna, Janome, Brother, Bernina, Pfaff, and others. But, you will pay more!
You also can't really go wrong with a Kenmore for the price - they are solid machines more for piecing than quilting your own.
I'm sure you can get more extensive advice from others on the board! Good luck!