Hi, apart from Shelly's really good recommendation, and if you're looking at branching out from the brands above, I found one really good, fairly priced quilting machine, (from a recent research I did for another question here on wize). The Singer 140Q FS comes highly recommended for serious quilters. It features 24 built-in stitch patterns, straight stitch lock designed specifically for quilters, quilting table or free arm two needle positions. It currently retailing at around the range of $ 140 - $ 150. Other features include;

5-Step Button Hole
Front Load Bobbin
Adjustable Pressure
Carry Handle
Free-Arm
Needle Threader
Snap-on Presser Feet
Feed Cover Plate
1/4-Inch Foot
Even Feed Foot
Zipper Foot
Embroidery and Darning Foot
Special Purpose Foot
Buttonhole Foot
General Purpose Foot
Blindstitch Hem Foot
Needles
Bobbins
Buttonhole Opener/Brush
Quilting Guide
Large Screwdriver
Small Screwdriver
Foot Control

:)

This one is by Janome and moderately priced -- The White Quilter's Machine Model 1740 sewing machine proves that good things can come in small packages. It's featherweight, but for such a small sewing machine, it certainly has a lot of big machine features.