Halo. It's been turned into a household name now, with nearly everyone knowing who Master Chief is - all around the world. There has been much controversy over why exactly Halo is such an admired and revered series.
Two major sides exist - those that praise Halo as the messiah of shooting games and defend every glitch, bug, and gameplay error there could be. There's also the side of people who think Halo is just a huge ball of hype, driven by the Katamari Damacy, if you will, that is the Bungie marketing team. There has been no consensus and will most likely never be one.
No matter what side you're on, you have to admit that Halo is a solid FPS. It's got some great elements - a good balance of guns, grenades, vehicles, and the other such stuff that makes up a shooter. It hasn't really brought in anything revolutionary (although it can be argued that the Forge mode in Halo 3 is quite interesting) but it has brought in a great playing experience. The games have routinely gotten high scores from game review sites. Blowing things up with plasma grenades, whether those things are aliens or your friends on Xbox Live, seems to be a solid formula.
Of course, there is the argument that online play is the only reason that Halo is so successful. Many shooters are often praised for having better gameplay than Halo, or at least as good. For example, Half-Life 2 was simply amazing. But, these games don't have something that Halo does - an excellent online component. Live makes sure that you meet fellow gamers and are soon able to snipe their head off while taunting them. Fun, eh? This, it seems to me, is a crucial success factor to the series.
If Halo began as a single-player campaign only game, it'd definitely be less popular than it is now. The huge fanbase and community is an integral part to why everyone loves Halo. Everyone loves Halo because, well, everyone loves Halo.
Oh, and it's a pretty good game too.
