Web Application Vulnerability Assessment Tools

Greetings list,

I'm in the process of evaluating web application vulnerability assessment
tools and was wondering if you would be willing to share advice with me
regarding tools available and how they've worked in your experience.  I'm
looking for a tool to scan web applications for SQL injection, scripting
attacks, buffer overflows, etc...  It would be nice to find a tool that
could be used by the security group to do black box testing and something
that could also be used by the application development team for white box
testing.

Thanks in advance,
-Brett