Windows only: I recently featured step by step instructions on how to root your EPIC 4G. It’s just gotten easier with Windows program SuperOneClick – The easiest, most universal rooting app I’ve seen yet.
SuperOneClick, works on all Android phones except seven, with little or no work required. Just download it, put your phone in USB debugging mode, plug it in, and go (to put your phone in USB debugging mode, just head to Settings > Applications > Development and check USB Debugging). Also, make sure to umount your SD card before rooting with SuperOneClick.
Six of the Seven incompatible phones (Specifically the EVO, Droid Incredible, Desire, Aria, Droid Eris, and Wildfire) can all still be rooted with methods previously mentioned on LifeHacker, so if you’re in that boat, you still have a perfectly capable one-click rooting solution. Unfortunately, users of the T-Mobile G2 are the only ones currently left out of the party.
SuperOneClick is a free download for Windows only, though a Linux version is planned for the next release and Mac support is on the wish list. Note that you need an account at the XDA-Developers forums to download the app.
SuperOneClick [XDA-Developers via LifeHacker]