this is a pretty tough question because pricing/quality really varies with location.
On the east coast they get much faster DSL/quality than us mountain people (CO) for about the same price.
On the other hand, lots of our AT&T @home cable users are much happier than those on the east coast.
Sometimes cable companies out here offer much better deals than the same ones out there. For instance, Adelphia
gives great cable service here, but they supposedly suck elsewhere. It really depends on the location.
My advice is shop around in your local area and talk to people in your local area to see what they've done. Chances are someone's already done the research for you. Otherwise just get on the phone, ask lots of questions about pricing/quality/availability. If you're paying 40-50/month, expect at least 768-1.5 mbps of bandwidth using DSL or cable. Any less than that and you're getting ripped off. Just make sure to evalulate all the options in your area.
Good luck.