Knowledgeable Army has a great post covering the reporting options in Great Plains. If you are new to Great Plains, take a look here to see all the various reporting options.
I’d just like to add one more, SQL Reporting Services. Reporting Services is poised to steal a lot of pieces from Crystal Reports due to inclusion with SQL Server, Visual Studio interface and generous licensing access. Also, Great Plains is starting to provide reporting packs for Reporting Services. Something they never did with Crystal.