I have had a sewing machine for years, and it's always good to have one on hand for when you need it. I know here in Avon, we have a huge JoAnn Fabric store that carries a very large selection for machines. I would suggest going in and talking with someone in a place like that. They will even let you sew on them and try them out. Then, if found one you liked, you could go back and so some searching online to see if you can get it cheaper somewhere else.
I've never used a computerized one or a serger. Mine is very simple and doesn't have a lot of fancy attachments. I would think about what kinds of things you need....do you need one that makes button holes? is good on embrodery? has lots of decorative stitches? Maybe make a list of what you think you'll use the most and then just go in and spend some time checking them out.
My grandmother always used Singer brand machines and that's pretty much the only brand I've used. Good luck! Feel free to PM me if you have any other questions.
K.