there are two ways to approach your selection:
-shop for "must-have" features and then narrow it down to the machine(s) which have them. select based on availability of the post-purchase support you know you'll need and price. test drive if possible. i can guarantee this will be the most expensive method of selection.
-set your budget and look ONLY at machines available at that cost or less. do NOT allow yourself to peek at anything more expensive. (once you do, there's no going back. LOL LOL LOL) narrow it down to the machines offering the most features within the cost limit. select based on availability of the post-purchase support you know you'll need and price. test drive if possible.
when i was searching, it narrowed down to Janome (best prices for available features), Viking (can use the widest variety of file formats), and Brother (soooooo many models to choose from, decently priced, and waaaaaaaaaaaaaaaay more FREE patterns available online than for any of the other formats.)
your search may narrow things down to a different list.
above all, take your time. once that craving sets in, it's tough to force yourself to wait until you are sure you'll be tickled pink by your final choice. if you cave in to the craving too soon, you may end up kicking yourself.
it took me more than a year to pick mine. i know i made the right choice for me because no matter what else i looked at, i kept coming back to the one i eventually bought. to this day, i have no regrets.