I think you are seeing a lot of us giving thumbs up for our personal likes for machines. I think starting with a list of what you find important features, price range, etc. is the best place to start. I would then make a "test drive kit" to take when you test drive your machines. I also am a huge believer of controlled experimentation. All the anecdotal advice you are given really is nice but when it comes down to it, you have to use the darn thing.
I really am a Pfaff fan, hate Berninas for a lot of reasons (doesn't make them bad machines, just not for me), bought my daughter a Janome (DC2010, try it you might like it, the price was hard to beat), etc. The off-the-shelf machines at Walmart look like a good deal and you might be lucky to get a good one, but usually you get what you pay for. Also, Walmart and places like that do not service your machine. You would have to find someone that would. Your personal requirments might be different than mine. I also look at the dealer (how long have they been in business, local or not, are they going to be around to honor those service agreements, etc.).
I know this sounds like such a daunting process. Don't impulse buy or let someone else tell you what you should pick. Because I was very new, I went by the advice of someone that I thought would know. I ended up with a DOG of a first machine (Singer) that never worked right, they repair people even gave up on it. She couldn't understand it because her Singer was wonderful, never needed adjustment or repair. (Then I saw her machine. Of course it was wonderful. All metal construction, industrial, built like a tank. The one I bought was all plastic gears, never timed right, etc.) Learn from my mistakes.
I would also take a machine out of the box at the store and try it. The one you test drive can be wonderful and the one you get home may has issues. Most places understand, those that don't probably aren't the place I'd want to spend money.