Not entirely sure how weapons were distributed amongst the Teenage Mutant Ninja Turtles, but it always seemed like Donatello drew the short stick (*ducks to avoid barrage of tomatoes*). All of the turtles received weapons that had steel as major components and could dish out some serious damage - Leonardo got two swords, for god's sake (even Uma Thurman only needed one). But nerdy Donatello got a big stick someone found in the alley behind Sbarro's (technical name: bo staff, but c'mon). Didn't really seem fair. Until Teenage Mutant Ninja Turtles came out for the NES...
All of the weapons in the game seem to do about the same amount of damage to enemies, so the only real difference between them is their reach. While Raphael spins his sai at an embarrassingly close range, Donatello can dominate bosses without ever needing to get anywhere near them. It's so bad that the game is pretty pointless if you let Donatello die - if you couldn't beat a level with him, what are the odds you'll be able to get any further with Michelangelo's nunchucks? Or maybe you're swimming through a field of electric seaweed, in which case, it doesn't even matter.
There are a lot of great, powerful weapons in Castlevania: Symphony of the Night - I mean, Dracula probably really regrets filling his monsters with tons of loot, and not evicting that lone librarian in the middle of his haunted, demon-filled nightmare castle. But none compare to Crissaegrim - a sword that swings four times every time you attack. This alone doesn't sound like much, but the beauty in the horrible-to-pronounce Crissaegrim (blame Tolkien) is that it's one-handed - meaning, if you're patient enough, you can equip two at once. With two of these things, Castlevania sorta stops being a game, and becomes more of a butcher shop simulator.
Smash Bros. is a chaotic enough game as it is, without giant, Thor-like hammers raining down on the tiny platform that is the only thing standing between you and certain death. The Hammer turned you from an average plumber/humanoid fox/F-Zero driver into an unstoppable god of destruction, while everyone else helplessly grabbed for Mr. Saturns and those stupid bumper things.
Thank god there were options to specify exactly which items you wanted to appear in multiplayer - Hammers are the first thing gone in most peoples lists. Although, if you really want to experience Smash Bros. at its finest: Final Destination, only Hammers. Welcome to Hell.
Maybe the most infamous overpowered weapon of all-time, the AWP was the source of constant frustration, swearing, and inappropriate slurs during many a Counter-Strike match. It was a long-range, one-hit kill weapon that even mediocre players could use to dominate a map. It's really amazing how insightful people can get about your sexuality simply from your weapon choice in a videogame.