BEFORE EVEN CONSIDERING ANYTHING, REALIZE THIS HAS THE RISK OF BRICKING A WII. NEITHER &T NOR I WILL BE RESPONSIBLE FOR YOUR ACTIONS
SWIM will admit he has done this succeccfully with LU 101 Wii (bought on date of release) with firmware 4.2
Want to watch .avi's on yours wii?
Want to p1r4t3 games?
Want to be able to do as you wish with international games?
Prerequisites
First, we need to get some infos off of your Wii:
1. What is your Wii's Firmware:

2. What is your Wii's serial number (this affects your chipset and the ability to play DVD+/-R):

The
OLDER THE SERIAL, THE BETTER
Now to actually hacking:
There are several methods of hacking from the Twilight Hack to Bannerbomb
BannberbombFirmware 4.1 and Below, use v1. 4.2 uses v2 4.3 users, please refer to separate post (last post)
Place on an SD card and when go to the SD card menu on the Wii. It will ask you for a prompt and then start the installation process.
Get Bootmii and DVDX when prompted on the installation screen (unless your Drive and chipset suck, even still get BootMii)
If all goes successful, it should look like this:

You now have taken the first step to fully hacking your Wii.
Comments
In order for one to be able to use things like USB Loader, Neogamma, and wad installer, one needs the coding to be able to read and perform those functionalities.
In order to do this, we much restore a buggy version of IOS 37 and IOS 36 which allows the installation of faultily checked signatures
For all users with 4.2 and below, download Trucha bug Restorer v1.1 and run in the Homebrew Channel
Trucha Bug Restorer Links
Go to Step 6 and use Anytitle Deleter to delete those IOS's, cIOS 222 is for USB loader
PM ME for a link to good ISO's
If there is anything I have forgotten, please remind me.
Super Smash Bros
Indiana Pwns
These are both as simple as Bannerbomb and the Twilight Hack, but like Twilight require some green.
Thank you for reminding me. That's what I forgot. Also SaveMii works if one has already fucked up, but costs money.