1. It's constantly fast-paced. In other sports (especially football and baseball) there are many breaks between plays. There may be short bursts of speed or great athleticism, but then the play's over, and everyone gets to rest again. Hockey is a game where everyone's constantly moving. The only stoppage of play is when the refs blow the whistle for a penalty; and even then there's a quick face-off and play continues. Line changes are done on the fly. All the players on the ice are moving all the time. Players typically take less than one minute shifts- and trust me, when you come off the ice after skating hard for one minute, you are tired!
2. Scoring a goal is the right level of difficulty. In some sports it's too easy to score, while in other sports it's too hard. For example, I think it's too easy to score in basketball. The players are tall and can easily dunk the ball and scores get ridiculously high. When one teams gets the ball, they get a basket more often than not. On the other hand, in professional soccer, it's too hard to score a goal. The ball gets booted back and forth across the field without even a goal scoring opportunity presenting itself for many minutes. In hockey, however, there's a huge range. Shutouts are not uncommon (especially if the team has a good goalie) yet scores can range from a few goals to several (7, 8, 9, even double digits). What's more, goals can be lucky or they can a be a result of a great shot that took amazing skill.
3. The Skill. I'm not saying that other sports don't take skill. Each one requires a different set of skills, of course, and the athletes who excel at their sports are truly phenomenal. But hockey is such a unique combination of skills. You need to be able to skate (forwards, backwards, crossovers, and you have to have explosive starts) while controlling a little puck on the end of a hockey stick. You have to be able to deke, pass, and shoot accurately, all while taking hits and checks from other players on the ice. Besides this, you have to be able to play good defense and you have to have the endurance for a 60 minute game.
4. The Intensity. The fights. The checks. The fact that the game is constantly flowing- one minute your team is on the offensive, rattling off shots at the goalie; the next minute the puck clears the zone and your defenseman or goalie has to make a great save. The power plays and penalty kills are exciting because the whole game strategy changes with the difference in the number of players. I love that the momentum of the game can change in a matter of seconds. It takes less than a second to score a goal in hockey, so no lead is safe. There's always the opportunity to come back, even until the final minutes of the game.
5. Moments to cheer for. One of the best parts about being a fan of hockey is that there's practically always something to cheer for. A great goal. A great save. A great defensive play. A fight. Besides cheering, there's an even better reaction that I like to call "the gasp". When a player misses a perfect pass. When a shot hits the crossbar and bounces out. When the puck is sitting in front of the net and the goalie doesn't see it. There's a collective gasp among the spectators because those things are the game-changing, nail-biting moments that hockey is all about.
There's more I could say about hockey because it's such an amazing sport. I think the reason it's not more popular is because it's a sport that a lot of people haven't experienced for themselves. You can go out in the yard and throw a football around or kick a soccer ball. You can play basketball in the driveway. It's harder to find an ice rink to go to. And hockey equipment is expensive. Not only do you need the essentials- skates, stick, puck, and helmet- you also need all kinds of other pads. So there are a lot of barriers to learning to play the game.
The thing is, you don't need to know all that much about hockey to enjoy it. The rules aren't that complicated, and the excitement and enthusiasm at a hockey game is contagious! If you've never taken the time to watch an NHL game, give hockey a chance. You might be surprised at how entertaining it is and maybe you'll even agree with me that hockey is the best sport ever!