A couple of years ago I bought myself a Janome 6600. I am now a dedicated Janome owner, but did a fair bit of shopping before I bought. One thing I did was to make a bunch of quilt sandwiches about 8" square and take them with me when I shopped. That way I could try out the machines. Here are a few reasons I ended up with a Janome:
- they were very popular all my home ec teacher friends which makes me think they are durable and easy to use
- the space between the machine body and needle was the largest at the time I bought - more room for shoving quilts through
- mine has an accufeed (top feed dogs) that are removable so I have more control
- all the features I had decided were must haves - needle up/down, lock stitch, needle thread cutter
- number one reason - the shop where I bought has a serviceman who loves his machines and knows them like his children; the service there is fabulous
If you do a search here for "sewing machine", you will find several threads where people have asked this exact question. The answers are as varied as the people, but you might find some advice that resonates. I think the main thing is to buy from a place where the service is good.