It's always funny to see PC gamers play halo for the first time. The reaction's almost always the same- "wait... why does everyone like this game?"
Because Halo was about seven years behind the times in terms of gameplay and storytelling.
The first game was inferior to other games when it came to graphics...or frames per second...but I think that was about it.
It was because of the MP and storyline which made the Halo series a huge success...
Now get a 360 and XBL and Halo 3.