I used to be a faithful user of Astro File Manager and ES File Explorer to do my daily file managing stuff. Now, each one of the aforementioned had it's pros and cons and I would have so much liked to frankenstein both of them into a single app. No I no longer need to use both of them, as there is an app in the market that does what I need and more.
You can exclude folders from media scanning, and you can even enable the root mode(in case you use a rooted phone) so that you can modify the system files freely. The application is skinable so you can download more skins if you don't like the default one.
The app also allows you to batch uninstall multiple apps and also to mount your local filesystem in read/write or read only modes.
One thing that I appreciate about File Expert is the lack of ads. They put up a popup first time you open the app where you can donate to them if you choose, and after that you won't see any ads or nags again.
This is one of the best apps I ever came across for Android.