I just have a pretty plain, middle of the line kenmore. It doesn't have a lot of fancy stitches, but it does have a few. For quilting though, I use straight stitch for piecing, buttonhole and zig-zag for applique (and piecing batting) and that is it.
The real deal-maker for me on a quilting machine is the ability to drop the feed dogs and FMQ. I have a smaller machine I use for classes and such, also a kenmore, 3/4 size, much less variety of stitches, but the real reason it would never hack it as my day-to-day machine is that it doesn't have feed dogs that drop.
I also like for a machine to be able to handle denim and many layers - and mine does.
My dream machine would have a larger throat space, and the ability to stop with the needle down automatically, plus slow/fast speed settings. I believe those last two were features on the Kenmore next price bracket up from mine, but I just didn't have the money.
More fancy stitches might be fun, but I wouldn't use them often enough to justify the price.