The "shared" issue is an urban legend. I believe it was PacBell that sued a cable company for using the "shared" argument - PacBell won.
Once a DSL connection passes the DSLAM, it too is shared. In fact, the Internet is shared.
Who's better is a local situation - depends on the ISP. Generally, cable has higher download speeds and DSL has lower latency. A number of cable companies are going to higher DL speeds soon. Comcast is changing from 4Mb to 6 Mb. Another is testing 12 Mb service. In the near term, cable will reign in the speed wars.
If you're a gamer or want to use VOIP, a DSL connection may serve you better. If you're into downloading music and video, then cable may be the better choice.