<p>What are the best open source (open source and commercial) reporting tools for ASP.NET similar to Crystal Reports for ASP.NET?</p>

As much as I despise Crystal Reports (we describe digging deep into it the seven layers of Crystal hell) -- it seems to be the best/most-flexible tool for the job. I hope someone comes along and knocks them off the block though.
Microsoft Reporting Services is an alternative, but didn't have the features we needed.