The Competition
ASTRO File Manager was long the favorite of Android users, and is still a solid app. It isn't quite as feature-filled as ES, however, and it is either free with ads or $3.99, which is hardly worth it for an app that doesn't do as much.
If you'd prefer something a bit more minimal, OI File Manager is a great choice. It doesn't have any of the bells and whistles that ES and ASTRO have, but it'll let you browse your files just fine, and it doesn't require any extra permissions (like accessing the internet) to do so. Its minimalism also makes it a bit more user friendly since it doesn't have nearly as many options to confuse more basic users.
Root Explorer is a must have for root users that don't use ES, since most other file managers can't get root access, which you need if you're editing system files. It's unnecessary if you have ES File Explorer, but it's the perfect companion to any other file manager if you've rooted your phone.
http://lifehacker.com/5825578/the-best-file-management-app-for-android