Joeshie, I'd just like to personally thank you for so eloquently summing up the exact reason Halo is so hated and loved. It is true, a vast number of the fans that hail Halo as the one of the best games in the first-person shooter genre are people who had never or rarely ever played an FPS before. Like you, I have been playing shooters since Wolfenstein3D and Doom on through Quake 3, Half-Life, Unreal Tournament and all the way up to the latest fair including Halo 3. I loved the first game in the series. Halo was a marvelous game that showed just how good a console shooter could be. One could argue that this fact alone doomed it to mediocrity but that's another debate. The point is, as Joeshie said, when Halo is compared to other games in it's genre outside of the Xbox or, hell, console base, it just doesn't have that feel of polish or greatness that the best FPS's have. For me, it also doesn't help Halo 3's case that Bungie seems to have lost their touch. Let's face it, Halo 2 and 3 were really lacking in the story aspect of the game. The first, though admittedly not deep, did have an interesting and intriguing story that left your imagination wondering. It had a certain epic feel to it. The direction they took the story in the sequels destroyed any sense of wonder I had in the characters. I know the average person that loves Halo isn't playing it for the story mode, and in that regard the game is a shining example of console multi-player. Hell, it's still one of the few series that still has split-screen for God's sake. Still, one has to admit it's story lacks the oomph games like Half-Life and Bioshock have. Regardless, Halo 3 is a fun game and I still love playing it at LANs, I just feel it doesn't deserve the level of praise it seems to get.
On side note, I guess one of the main reasons I couldn't get into the Halo story was that it felt way too much like the Starship Troopers story, in every regard. No, I don't mean that crappy movie from the 90's I mean the novel the film was based on that was written in the late 40's early 50's if I'm remembering correctly. The "bugs" in the book are essentially the Covenant, right down to the conglomerate of alien species, some having highly advanced technology and most being bi-pedal, and traveling across the universe in vessels. If you've read it, you'll understand how hard-pressed one would be to argue that when Bungie thought up Halo they didn't get most of their ideas from the Starship Troopers book.