The single worst part about halo's story wasn't the flood, it was the idea that the forunners invented the rings to kill everything else to sarve the flood.... genious.
I rewatched alien/aliens the other day and relized what people think is good sci-fi is as bad as what some people think is good video games. Not to say they aren't entertaining but really they're oozing with cheese and lameness (don't even get me started on star wars). Most video games have crappy stories, so instead of making them better they try to dilute them with fancey graphics or pathetic control gimicks a la Wii. I'm sick of this febreeze spray gaming. If this is really as big an industry as movies now they really gotta try harder to raise the bar.
On a side note, Halo 1&2 were very repetative and hard to push though, esspecially the library and level after level of the same crap. I look at Halo3 however the same way I look at Return of the king. The first two LOTRs made me fall asleep or only enjoy small bits out of the big picture. Once I watched the final movie I fell in love with the series. So in short if there's anyone new to Halo, just go online and find the video with all the cutscenes explaining the story then play ONLY the 3rd game. As it's the cummulative masterpiece they wanted from the start. Just as you think it might start getting repetative or boring it throws something new at you.
Crysis however says "look at the leaves while your running through the jungle, ohhhhhhhhh!".