11. Portal Gun
https://www.youtube.com/watch?v=lIhtoszZR9I By tagging surfaces with an entry and corresponding exit point, players can wreak space-warping havoc with this nifty little scientific marvel. You'll waste away the hours cruising around the roads of San Andreas wondering what sort of mischief you can get up to with this bad boy, with strategic portal placement resulting in a gag-reel of freeway-spanning pileups, high speed collisions and citizens plunging to their deaths in hilariously inventive ways. Just be sure not to drop yourself into an endless loop unless you don't mind the amusing exercise in vertigo.