Most of the serious quilters that I know own Berninas. The straight stitch quality with a Bernina is fantastic, and Bernina has identified the quilters as a group that they want to woo. Berninas last forever too, they are a very high quality company.
You can make good quilts and garments on most machines, however. Bernina, Husqvarna, Pfaff, Janome, are all good names with solid reputations. I think you need to take the time to test drive a lot of different brands and figure out what features you really want and what brands fit you best. And take your time if you can.
Do you want to be able to do embroidery? What about machine quilting - maybe consider a long arm. Or free motion quilting, one of the major brands, I forget which, came out with a machine that has features specifically to enhance free motion quilting. It looks really cool. Even the little things, like auto-threading, needle up/down, thread snips, multiple needle positions, or the size of the foot pedal can make a big difference in how much you like your machine.
For garment sewing, a serger is nice, no question. Again, I would test drive machines. See how easy they are to thread, to convert to a rolled hem, to adjust the tension. You can buy a nice serger for $500 or less IMO. More than that gets you auto-tensioning and/or auto-threading. If a machine that is more automated helps you sew more, better and faster, maybe it is a better buy for you.
There is a website on sewing, Pattern Review
that has pages and pages of machine reviews posted by sewing machine owners. I think it is super helpful in figuring out what machines are popular and whether a particular model is likely to be a lemon.
Good luck! How lucky you are, to be shopping for a new machine!