Halo is average. That's all there is to it, to be honest. It's an average story told by average characters (Except Johnson. He was awesome.) in a pretty standard Sci-Fi universe. There's nothing truly innovative about the gameplay, the graphics are good but not great, and most of the characters really aren't that compelling. That's not to say that it isn't fun, however. I wholeheartedly admit to enjoying the games, and it does have a great multiplayer system, but you can't expect multiplayer to carry the game unless that's all there is, as in games like Team Fortress 2. Again, it's just an average game with a massive hoard of fanboys.
Maybe you haven't played Halo...
THEN MAYBE YOU'RE MISSING OUT. Halo could be considered one of the most famous video games in the world, standing next to games like World of Warcraft and Final Fantasy. It's got several books, an anime, comics, and maybe even a movie dedicated to it, and don't forget all the Fan Fiction. If you're reading this review, it can only mean that you know Halo, but aren't sure if you really want to delve into the thick of the game. Or maybe you love it and are just here for laughs. If you're a PS 3 Fanboy you hate Halo without ever considering the game play or the story. I'll admit, the game is fairly linear in its play (Aren't most games) it's pointed out that sometimes Halo is a little too direct and thoughtless, maybe that is true? It's honestly all about taste. You don't need to take the gameplay so seriously, its just suppose to be entertainment, but maybe it's not too engaging for you (That is not to say it is not DIFFICULT, which all you need to do is set the "Legendary" setting). Personally, where the game REALLY shines, is the story. It can be considered partially rehashed from earlier games, like doom. The "A Space Marine Is You" is nothing new, shooting your way through hoardes of Aliens? Seen it before. But the real juice is part drama, and part WOW. It has some beautiful graphics, especially in the later games. And there's a lot in the story that simply surprises you. If you're a fan of science fiction, you'll no doubt be captivated by all the high-tech gadgetry and such. And then you might get yourselves to the Books, a whole world of thriller, plot lines that you can keep you from even setting down the books. Things might become a whole world of "Wait, what happened between #X and #X?" since a lot of the story isn't even explained in the game. The interaction between characters is nothing short of moving, it's okay to cry during Halo if you're a guy, it's Manly tears there. The music is nothing short of stunning, every scene is almost perfectly accented with the most appropriate tone, and it can go from classical to rock n' roll whenever the situation dictates.