A few years ago my husband found a Genie 354 at a garage sale. It's not lightweight, but it was compact -- until I had to replace the foot pedal. That's when I dug out a scrap booking case on wheels. It's great. My machine, my seat cushion, new pedal, box of notions (thread, scissors, ripper, etc) and project all fit the case. It's not necessarily what I wanted, but the price was right (I bought a new school supply box, pair of small scissor, seam ripper and pin cushion to leave with the sewing machine).
Now, having said that, I considered a featherweight -- but many(most?) don't zigzag. But I'm a quilter, "I don't need a zigzag." Then I'm reminded of the class that I TAUGHT!!! that needed zig zag (applecore using the Wonder Arc pattern). Also, it's hard to applique with a straight stitch only machine. So, if you go for a featherweight make sure you still have something you can take to classes/retreats on those occasions when you'll use the zigzag feature.
Oh -- the machine I was looking at is the Janome 7330, but decided I should save my money for the long arm I eventually want to buy.