I can recommend a few good machines: Janome Jem (the older mechanical one was my fave), the smaller, lightweight Brother machines (I have one and I'm very impressed with it), and the Babylock Sofia2. All are quality lightweight machines.

If you prefer vintage, then I second Numa regarding the Singer 301. I have one, and it sews a great stitch. Honestly, I never take it out of the house though. I love looking at it in it's special place in my sewing room too much to move it.