A bunch of four, lousy, cheating pokemon trainers who you have to defeat before facing the champion. They think they're so great just because they use cheap pokemon with even cheaper movesets. The only way to defeat them is using Lv.100 pokemon, cheating, or using full restores after every battle. Believe it or not, you have to defeat these guys in all the Pokemon training games from Red, to Platinum. If you can defeat these four trainers without using any of the above methods, then you must be really good at this!
n00b: "Darn, these elite four losers just pwned my team!"
Another Guy: "You're doing it all wrong! Look, you just KO their pokemon using a hack, and there!"
n00b: "Whoa! I can do that!?
Another Guy: "Yeah, if only you weren't such a n00b."
The nukks you have to face at the end of the blue, red, and yellow versions of Pokemon.
You also fight these guys in silver, gold, crystal, etc...before getting into Kanto.
Man the Elite Four are some pretty tuff nukks.