I love hockey. I love the combination of speed, strength, and finesse it takes to play it well. I love how the game is so fluid yet so physical. And, like any other red-blooded male, I love the fights. A question I have been having is why fighting developed in hockey and became such an integral part of the sport but not in any other major sport.
Fighting in hockey is generally a retaliatory action. Player A generally starts a fight with Player B because of a perceived dirty or excessive hit on a star player from Player A's team who is generally regarded as off-limits. The thought is a heavy hitter on a team that is playing the Avalanche will think twice about laying out Paul Stastny for fear of having to fight Ian Lapperierre.
Other sports probably didn't develop fighting as a legitimate means of retaliation because there are different costs and benefits associated with different actions. Most other sports have systems in place that raise the cost of dirty or especially rough hits. In basketball, football, and soccer, the team that gets hit can gain field position, have the possibility of more points (i.e. foul shots) or have the offending player taken off the field entirely. In basketball or soccer it even makes sense for a team to invite rough play because the cost to the other team for fouling is so great, thus equaling a high benefit for receiving a foul. Baseball is probably closer to hockey in that a pitcher who intentionally hits a batter is likely to be met with a fastball to the arm or midsection. In addition, there is the distinct possibility of ejection for throwing at a batter.
Hockey is different because of the nature of its hits. A hit doesn't have to be illegal to warrant a fight. It simply has to be unwanted, as is the case for many stars who are supposed to be protected due to their high value to the team and the risk of injury from a hit. There is no assigned penalty for hitting someone who is "off-limits" so the players must police themselves. Rather than play a game of escalating hits, an enforcer will square off with the hitter and settle the issue right then and there, and then get back to playing hockey.