I'm in love with my singer 66.. Though she doesn't have drop down feed dogs, reverse, and nor is she portable, but she hums.. She is easy to take care of, and she performs like she is at Lincoln Center. She doesn't grab my threads, doesn't skip stitches, and all she asks in return is a little oil now, and then. It also helps if she is plugged in. She gets very stubborn if she has no current going to her.
I also have two Singer 99's.. I fell in love with my first, and was at a garage sale two weeks ago, and another came home with me.. I hope to give one away to a niece, but am waiting for one of them to mention the need.. They are different models of the 99's. One has reverse, and the other doesn't, but has a bent wood case. Both were very well taken care of.. Both were $25.. One from a thrift store, and the other from a tag sale.
Since I do applique sometimes, I have a green Singer from the UK.. I only use her for her zig zag capabilities..