Is the out of box Salesforce reporting tool not working for you? Our appexchnage has some tools that might help you with complex reports:https://appexchange.salesforce.com/category/dashboards e.g. https://appexchange.salesforce.com/listingDetail?listingId=a0N30000009wJtfEAE&tab=r
e.g. https://appexchange.salesforce.com/listingDetail?listingId=a0N30000009wJtfEAE&tab=r