It depends on what type of service is offered in your area. You can pay extra for more bandwidth on EITHER type of service, depending on which providers are available and what they offer. I'd lean towards DSL, because you won't have to share your bandwidth with nearby users as you do with cable, plus there is more security since your line is dedicated and not shared with other people, however the availability of DSL is rather limited in comparison to cable since you have to live within a certain distance of the telephone switches in order to get DSL.

cable is unless you are really close to the CO. I have had it faster on DSl before.

The fastest networks are Fiber to the Home which can get 100 MBPS. Japans networks have that and are the same price or cheaper than our cable connections. The only one building it here is Verizon. AT&T is beginning Fiber to the Node which gets about 25 MBPS which is also faster than most cable, but there is not much of it yet.

Cable, there are better quality lines used to route the information.

cable.

That is probably going to vary by country and location within that country. Here in the UK I'm fairly sure the fastest downloads are from 50Mbps cable. You can compare all the offerings here:

http://www.thinkbroadband.com/isps.html

cable... i use dsl now and my dsl is even faster than cable.