I use a Singer. I've had it for about 2 years now, and absolutely love it!
The only issue I've run into is the back stitch pedal not working recently. I blame that on my sister though, since she borrowed it for a huge quilting project and is NOT gentle with machines 8/

thanks so much! you are the second person to recommend a singer!

It depends on what you intend to do. For light fabrics the ones with nylon gears are fine, but if you intend to use it for heavier fabrics they can strip or burn out quickly.
A suggestion is to look to your local freecycle, I've gotten a few decent older models that way.

thanks!