According to me it all depends on the vendor you prefer. A number of great reporting tools exist.

Oracle Discoverer is Oracle's ad hoc query tool. This tool allows you as a developer to create an end user layer, which acts as the end-user view of you db. I like Discoverer's ad hoc query ability, but if your users like printing reports and graphs, this tool will be frustrating.

Business Objects is another excellent tool for user reporting and ad hoc querying. If your budget allows get BO.

Both these tools allow users to user the web as front-end.