SQL Authentication vs. Windows Authentication.

[stardv]

We are setting up Web server first time in the company since we hosted it at other place before. I would like to get some input on making a decision whether to have SQL authentication on DB level where I have separate accounts created on SQL DB or create Windows Account for ASP.NET impersonation to work under and have Integrated Security on DB level, or just authorize NETWORK SERVICE account on Win 2003 to communicate with Db on behalf of the application

Thank you for your input