As others have said, it's very subjective. So much depends on your personal tastes, how you plan to use it, and your budget.
I own 7 machines and by far my favorite is the Brother PQ1500. It's a straight-stitch only, big workhorse. If it ever dies beyond repair I'll immediately replace it. However, you may want decorative stitches, or a smaller machine to lug to classes and retreats, or it may not fit your budget.