Bernina 830 is great for piecing, quilting,almost all metal, has reverse, zig and many other stitches and if you hook your arm under the opening you can actually lift it with out breaking your back. It is a machine you can do all aspects of quilting with plus more. A good used Bernina 830 can easily run $800.
Some other machines are the Singer 401, Singer rocketteer but they are heavy.
Other Singers are fun too, 301, 221 Feather weight but might not have zig zag, do not drop the feed dogs, or not have reverse etc.
I like the all metal Pfaff and Elna too but sometime sit is harder to find parts for some of them.
For the newer machines, we are pretty sold on the Janomes.