For those of you who want to get most out of your Galaxy S3 GT-i9300, you will certainly want to root your Galaxy S3. Rooting your Galaxy S3 gives you lots of benefits like full control over your phone, ability to install custom ROMs, and a whole lot more. (If you would like a longer video explanation of what rooting does, please see this video “Why Root My Android Smartphone?”.
See updated new root method for Jelly Bean and ICS!
For AT&T, Sprint, T-Mobile, and T-Mobile Galaxy S3 (or Canadian dual-core S3), please see How to Root U.S./Canadian Galaxy S3!