We assume, nay, we trust, you are not talking about one of the electric machines that mixes the egg and flour and extrudes pasta in various shapes at the end of the process. To quote Marcella Hazan, "What emerges is a mucilaginous and totally contemptible product, and moreover, the contraption is an infuriating nuisance to clean."
What you’re looking for is a stable machine that uses two parallel cylinders to knead and thin the dough, and generally includes two sets of cutters - one narrow for tagliolini or spaghetti and one wider for fettuccine. There really aren’t that many brands of pasta machine on the market in this country.
The Trattorina Pasta Machine appears to be the Cadillac of the pasta machines (if anyone still refers to the Cadillac of a category). It has nine thickness settings and is very sturdy. You can purchase a separate ravioli cutter for it.
The Villeware line, including the Al Dente model and the Imperia, are at the lower end of the spectrum. There are also other cutting heads that can be purchased separately for the Imperia to cut tagliatelle, millegnocchi, trenette, angel hair and other shapes. The Al Dente can be purchased as a package deal that includes a variety of cutting heads.
The seems to come in somewhere in the middle, in both price ($30) and quality. You can purchase a motor separately to save the chore of hand-cranking, as well as additional cutting heads.
Another option, if you already have a KitchenAid stand mixer taking up space on your counter, is to purchase a set of pasta rollers and cutters that attach to the mixer’s hub and work off its motor. The three-piece set is made by the same company, Mercato, that makes the Atlas machine, and includes the kneading and thinning rollers and a head that cuts fettuccine and one that cuts linguini fini. The set costs $100, but (since you’ve already made the investment in the mixer) is less expensive than the better machines when purchased with a motor drive.
We’re pretty happy with our Atlas pasta maker, and don’t mind turning the crank by hand.