In case you're too lazy to read this review, here's a list of five games that are not as good as Castle Crashers:
The Simpsons Arcade Game
River City Ransom
It's hard to imagine that a 2D, side-scrolling beat-em-up would require 3 years of development time. And yet Castle Crashers started its lengthy cycle way back in 2005. Sure, the development team is made up of like six people, but this is a beat-em-up! You run to the right, guys run in from the left and you slam on buttons until they die. Not exactly a complex experience. And yet The Behemoth (the developers who also brought us Alien Hominid), have managed to bring the beat-em-up to a new level. This is the best beat-em-up ever made.
Like most beat-em-ups, the storyline of Castle Crashers is about as straight forward as you can get. You and your friends are sitting in a medieval tavern when suddenly a wounded knight bursts in, bloody arrow in his back, and falls down dead. War has erupted and an evil empire has stolen the princesses of your land. It's up to your and your buddies to get them back.