My personal opinion... I have had both, both the phone company and cable company SUCK to deal with if you have problems. I have had SOOOO many disasters dealing with Ameritech, and I would tell anyone NOT TO GET AMERITECH, if you can help it.
On a preformance level, it depends when you do your surfing. Cable fluxes according to usage, so at peak times it is slower, where as DSL is dedicated to your house so it is always consistant. Cable is faster when no one is on, and DSL is faster when a lot of people are on. Cable is also nice because it is always on and you don't have to connect to it. I personally would lean towards cable, but I would see what specials they are running, usually you can get at least one of them for about $30 a month for a while as opposed to the usual $50.