It really depends on your requirements. What is it that you need? Like any software SP is a tool, just like home improvement you don't go out buy a tool and than try to use it for what ever task is in front of you (you might end up with a screw driver while you really needed a hammer). So I could make a list of Document Management, Content Management, Intranet, etc software but the correct answer depends on your needs since there are lots of choose and all (some) have there own strong and weak points.
SP is a mesh up of several software suits slowly coming to getter, it is getting better every release. SP could also be the right choice depending in your needs. Mainly work group portals but those tend to fail (as in not being used) since most of the time there is no proper business case nor business processes in place to support the grand idea