Ever seen all those fake pictures and fake guides on how to unlock Luigi in Super Mario Sunshine? Well, now you can make your own way to unlock Luigi and post it in this thread! The only rules are to have fun!
...so if I don't have fun am I breaking the rules?
Never mind I'm thinking about this too hard.

I'll begin:
To unlock Luigi, first you must put in the Luigi's Mansion disc. Load up a completed file and then go to the main room and save. While the game is saving, take the disc out and quickly put in the Super Mario Sunshine disc. While you are doing this you must be holding down the A and Y buttons while holding the C-stick down and the left trigger down slightly. If this is done correctly, the game will play the Luigi's mansion title screen theme but have the Super Mario Sunshine Title screen. Now, go to the left on the file select screen, and there will be a new screen with a box with an L on it. Hit it then go over to the other screen and select file B. While file B is loading shoot your Wii/Gamecube with a rocket launcher while screaming 'WEEGEE WILL RULE THE WORLD!' and if you did it right then the Wii/Gamecube should float up to space and Luigi will be playable. But you haven't got your Wii/Gamecube any more so the controller is gone too, so you can't play.

If you want to PLAY as Luigi then you must do it all up to the rocket launcher bit. Don't do that, instead go to the nearest manhole on Super Mario Sunshine and then run around it for 64 minutes. At exactly 64.64 go into the manhole, and then you should warp to a new level called 'Luigi returns'. Select the 2nd Shine Sprite and then you'll be in Bianco Hills. Walk into any solid object for 2 hours and Luigi should pop out of the solid object and throw Mario into the solid object. Then you can play as Luigi!
...Well, for that stage anyway. Luigi cannot use F.L.U.U.D and the game has a 60% chance of crashing every time you press a button. If you want to fix this, just plug the Microphone for Mario Party 6 in and scream into it 'WEEGEE' and then the game will reset. The game will be Super Luigi Sunshine and you will play as Luigi for the entire game. Now Luigi can use F.L.U.U.D, but due to unfinished coding he will not be able to move. If you try to move then 12 bags of potato chips will suddenly pop out of the TV and your console will explode. Then you will be dead. But look on the bright side, you had Super Luigi Sunshine for a second.

Okay, here's what you do.

First of all, you need to have a Luigi's Mansion save file along with Mario Sunshine. Easy enough, but now things get difficult. You need  to collect only two Shine Sprites, and only play on the second save file out of the three available. There you need to go the statue where you enter Bianco Hills. Run around that statue exactly 64 times. Now sadly, this next part takes some patience. You need to play on like normal until you get to Sirena Beach. On the second star mission you need to enter Hotel Delfino. And find a hotel room (Or bathroom) with a mirror. Then you need to plug in a microphone into the Wii (Or just use the second memory card slot for Gamecube). But you need to whisper "Luigi is love, Luigi is life" into the reflection. This took me 64 tries. But Luigi will walk up behind you, and yell "SUPER LUIGI SUNSHINE!" and then the game will reset by itself, When you start it again you need to hold down the L button as you select a file, and you'll start the game as Luigi!

First ,put in Super Smash Bros. Melee ,then select Luigi ,then go through either Classic ,Adventure ,or all-star mode on easy ,then put in Super Mario Sunshine ,select the file you already started ,and there you go ,you get to play as Luigi in Super Mario Sunshine ,note that Luigi will have FLUDD equipped ,but Luigi's Moves are different.

RAAAAAAGE! I hate you back arrows ;~;

Anyways,
Pssst, pssst, kid, pssst, kid! HEY KID! Wanna be Luigi on Super Mario sunshine? No? Too bad.


Play as Luigi on every game you can on every Nintendo HOME console (No handhelds) this includes Super Mario 64. Now 100% all of them.

Now plug in Super Mario Sunshine, you should notice that instead of Nintendo showing up it's SEGA, Yeah that's some weird crap right? This has to show up. Now get to the part where you're about to get arrested, but before the trial cut-scene shows up plug in that GBA to GameCube cord with a game of Phoniex Wright on it. Now play the cut-scene and on the GBA press the button that makes you go OBJECTION!!! The screen should flicker for a second and then the screen will say GUILTY! GAME OVER! Then it crashes. When you boot it up again, the game should be called Super Luigi Sunshine. As you play Shadow Mario is there but.... at the end of the game where he shows up Bowser Jr.? Well at that part, Shadow Mario turns into regular Mario, creepy crap.

EDIT: Every method in this thread works, this is just the best one

First off, after selecting your save data, you have to plug a N64 controller into your 4th controller port. Then, you have to go to the final boss level. It will show a new cutscene with Luigi at the end. Go through the level as usual, and after you win, Luigi will fly off the screen. What you do next is with the N64 controller (it won't work using your hand) you open the CD tray. Flip the disc around, and start it up with no controllers. Luigi will pop up on the screen, and you then have to plug in 2 GameCube controllers in, and press A and B on both controllers. After you do that, you will still be controlling Mario in the game. Now, run the entire perimeter of the starting island three times. Luigi will now be in the 400th Yoshi egg. Break open 399 Yoshi eggs. Now, while on that Yoshi, you must jump between any two close buildings for 50 seconds. Now you will hear Luigi cry out for you. Go break open the 400th egg, and you can now control Luigi!

Step 1: Insert Luigi's Mansion
Step 2: Die in the game and mash the the X button as fast as possible. 
Step 3: While the game is counting up how many times you pressed the X button, put in Super mario sunshine.
Step 4: Die in super mario sunshine and when you respawn you should have a glitched luigi. Die to fix the glitch and become Luigi

Why does this work? Well Luigi was SUPPOSED to be in Super Mario Sunshine as a prize for getting all of the Shine Sprites but the developers wanted to be A-holes so they made it that you just get a freaking postcard. Anyways. X is the 5th letter in relaxing. Which is on the postcard. When you die in Luigi's mansion and rapidly mash the X button. The gamecube itself stores the data un Luigi's mansion. When you pop in super mario sunshine, the game is tricked into thinking you're still in Luigi's mansion. And goes through s.m.s's code until it find luigi. Due to him being unavailable, you get a glitchy luigi that is fixed when you die.

Kinda long yet unrealistic. :

Great job, guys. I'm going to join in with another one ~

First of all, put a Super Smash Bros 64 cartridge into your Gamecube because that's definitely possible (I promise) and then unlock Luigi. Play with Luigi until Master hand and then make Luigi do a double backflip and then flip your Gamecube over and press the reset button. As the game is resetting quickly put the Super Mario Sunshine disk in and then mash the reset button 453 times before anything happens. If it's any different your console will explode so be careful.
Once you've done this, Super Mario Sunshine will load up in Japanese. Now instead of pressing start press X and Y and then turn off the console. Get a Gameboy Advance hooked up to the Gamecube, with it turned on and running Pokémon Red. Get into a battle with missingno then open the disk tray and flip over Super Mario Sunshine's disk. Start it up again and as it is turning on, switch off your GBA and then throw your TV at a wall because Luigi isn't actually in Super Mario Sunshine. trolololololol

OH EN GEE GEE! THEY REALESED A NEW PATCH!

To do the new patch, get the following: A nyan cat (Put a poptart on your cat for all I care) a Wii U, a Virtual boy, and Doritos, oh and a GameCube. Now shove it all into the GameCube, turn it on, and it will say: "Advertisement sell out DLC, $420.69" hit accept. NOW EVERYTHING IS A ADVERTISEMENT! Now, 100% everything. All three save files in under a second! (It's possible, legit) If done successfully, press 'A' over 9000 times, and punch yourself in the face. Quit your job and sleep for a few months. Then boot up the game and you can play as Luigi! 


Happy now? Hope that was worth it you evil turtle.