what do you what to accomplish with it? They come in all sorts of configurations. I have a boot patcher, a hemstitcher and a blind hemmer. Then I've go another that is just straight stitch - full speed ahead and that's it.
I'm considering getting a buttonholer, just because they are fun to watch. I was considering a chain stitch embroidery machine, but it sold before I could get there (400 miles away). There are some neat super long arm ones out there too, I know one person used them to quilt upholstery fabric before putting it on furniture.