Viking, Pfaff, Babylock Tiara are all the same machine as the Sweet Sixteen. If you didn't like the SS or had trouble with it, you'd just be repeating.
Babylock Regent and HandiQuilter Capri are twin machines.
Bailey is supposedly a stretched Janome machine.
Don't bother with the Juki Virtuoso - it's being superceded by the Miyabi 350 that has stitch regulation in the table similar to the Regent/Capri/now-discontinued Innova sit-down (table has 2 small optical sensors in it).
APQS also makes the George sit-down. Very serviceable. Great company.
Bernina is very pricey for a large head that's hard to see around, especially compared to the others.
My first choice would be a used or leftover Innova sitdown if you can find it. Second choice would be an APQS George if you don't mind the last of stitch regulation. Juki doesn't have the greatest support. HQ Capri/Babylock Regent might be an option but there are reports of issues with the stitch regulator so do your research.
If possible, test drive before you buy. You might be surprised how the sound of once machine vs. another or the intuitiveness of the controls makes a huge difference.