from
http://www.satelliteinsight.com/dsl.html
DSL And Cable Comparison
Advantages
DSL
DSL is cheaper than cable internet service!
Always-On Internet Connection 24/7. No dial up. No busy signals.
Connection is unique and speed is not affected by the number of users on- line at the same time. DSL speed stays consistent.
Upload speed is comparable to cable. One study indicated that dsl is faster than cable modem service.*
Customers can dial up services remotely when travelling.
Optional Static IP address supports server hosting for gaming, home office users, and telecommuters.
Surf the internet and talk on the phone at the same time.
* Based on a month-long benchmarking study by Keynote Systems, DSL was found to be 11% faster than cable modems.
Cable
Always-On Internet Connection 24/7. No dial up. No busy signals.
You can browse the Net, watch cable TV, and be on the phone at the same time.
Downloads up to 100x faster than a 28.8K modem; however, typical speeds tend to be much lower than the maximum. Speed potential is greater.
Cable provides bundled discounts for TV, Internet, and telephone services.
 Cable offers a much wider service area.
Disadvantages
DSL
Only as reliable as your phone line. Service may be subject to interruption by  severe weather.
Service is currently limited to an area within close proximity of local telephone  facilities. (18,000 feet or a little over 3 miles)
Cable
Service can be affected by the weather and reliability can be an issue.
Shared bandwidth causes speed slowdowns especially during periods of peak demand. The more users on the system at the same time, the slower the connection speed.
Shared bandwidth technology exposes users to privacy concerns.
Dynamic IP address does not support server hosting for web site, e-mail or gaming.
Keep in mind that no service is perfect. Cable offers greater speed potential; dsl offers an individual Internet connection with more consistent high speed and a greater measure of privacy and security.
Additional features, such as firewall protection, spam blocking software and anti-virus software make dsl a popular choice for new subscribers. The bottom line is ...
DSL is cheaper than cable.
While neither service guarantees download speed for residential service, dsl presently gives you more benefits than cable. Accordingly, it represents the best overall value for high speed internet service today.