The beauty of SharePoint is that this is a modular platform, that support add-ons to enrich your environment.
There are a huge number of add-ons available for FREE as well as commercial.
Here I will highlight my favorite (Free) Solutions / Features / Plug-in
1. Excel Export of a BCS / BDC list
Natively there is no option to export a BCS /BDC list from external data to excel
Use this solution http://exportexternallist.codeplex.com/
2. Adding Professional Graphs based on List data or SQL database
Adding the FusionChart Feature for SharePoint will give you a lot of free charting options to start with, using a new WebPart.
3. Interactive Charts using Google Visualization API
Example of how to add a GEO Map of your AD users
On this site you will find many more useful SharePoint utilities
4. SharePoint Permission Manager
5. AD Browser
Keep in mind that you have to enable the session state when implementing this WebPart.
More free stuff on this website.
More to come …
If you have interesting Solutions / Add-ons / WebPart, Please share yours.