I agree with "a" on this one. Halo is popular to diss on forums like these because it has such an obnoxious fanboy base. But don't let that cloud your judgement. Bungie's accomplishments with these games is immense and to be respected. Not only did they make a better mousetrap in terms of FPS design (really, the first control set that could rival keyboard and mouse), but they also established a "mascot" character for the Xbox in Master Chief.
I have little doubt that without that, the Xbox would have been a colossal disaster for Microsoft. It's so important to have some kind of figurehead that embodies the vision one has for a console, and Master Chief does that perfectly, as the Xbox brand has always seemed to be geared towards the adult gamer.
I'm gonna stick up for the story. Yep, it certainly mashes together lots of typical sci-fi elements. But it does so gleefully, and is self referential about it. Besides, great genre fiction is usually a mash up (Lord of the Rings was the ultimate mash up of folklore and mythology).
The voice work is not as bad as stated here either. The voice of Master Chief isn't going to win any awards, but that's an intentionally one dimensional character, and that dark, clipped "precise" voice suits exactly how they present the character. Cortana is voiced in a sorta mediocre way, but it actually works because she is an AI construct, after all.
It's easy to rip Halo if you want, because like so many other great games, it does lots of things very well, yet doesn't really do one thing exceptionally well. Zelda is having this problem now, IMO. Critics like those IGN dudes can't see past the fact that the game is a refined version of Ocarina of Time (nothing wrong with that), and they judge it much too harshly. Especially that one dude that kept saying "I play games for NEW EXPERIENCES." Um, that's nice, but I play games if they are fun, myself.
-Rob