Halo has been a big part of my gaming life. The first xbox game I played was Halo, and i loved it. I was more then excited when Halo 2 was released and only played these 2 games in LAN form with a punch of guys. I believe that this is the best way too really enjoy a multiplayer experience. 
 
Halo 3 really started up my joy of online gaming. It made me purchase games like L4D, TF2 and lot's more.  
 
Now Halo Reach. I love this game. I especially love the campaign. But I like Halo Reach as a "shooter" not exactly as a 'Halo' game. The main reason I think this is, is because of the shields and health system. BUT when you look past that its  a great game.