I think you're insane and incorrect, but I have to hear your answers to a couple questions...
"Halo wasn't the first to have vehicles. OWNED"
Obviously true, but you can't deny the quality of Halo's vehicles in comparison to other games. Games like Tribes inspired the original concept of Halo, and I was an absolute Tribes whore, but Halo's vehicles were more enjoyable to control and offered a much more complex physics simulation.
"Halo wasn't the first to have dual wielding. OWNED"
Do you understand dual wielding, though? Why not name the games you think beat Halo to the punch.
"Halo was a mishmash of all sci-fi cliches passing as it's story. OWNED"
So? It was presented very well for an FPS. The vast majority of FPS titles on the market don't exactly excel here either. The best FPS stories can be found in games that really aren't regular shooters (like Deus Ex, which had pretty terrible gunplay...)
"Halo had repetitive enviroments and gameplay. OWNED"
So, it's all about the visuals is it? First of all, Halo 2 does not suffer from this in most of its levels (those covenant homeworld levels were dull as hell, though) and secondly, visual repetition does not mean gameplay repetition. Assault on the Control Room in Halo 1 re-used so many set pieces, but each re-usage of those pieces presented a very different scenario. There is no argument here, as that's how it is. Of course, you probably weren't bothered by games that throw the same boring enemies (that do nothing but stand there) at you over and over again through a variety of environments. Screw gameplay variety, I want scenery changes!!!111
"Halo didn't have weapon restrictions first. OWNED"
I agree, but like I said, this isn't about individual features. It's the package. Choosing each one of Halo's features and saying "well, this game had THIS feature" and "that game had THAT feature" is missing the point. You can't just pick and choose. It's all or none.
"Halo didn't have a regenerative shield first. OWNED"
I'm drawing a blank here. I wish I had my collection handy so I could review each game to be certain, but for the major titles, I can't recall a single game that offered this same functionality.
"Halo wasn't the first to have decent physics. OWNED"
Halo's physics were better than decent, though. Physics and animation in PC FPS games was the absolute PITS prior to Halo. Do you really remember how awful most games looked in motion? There were other FPS titles with physics, but those physics simply weren't comparable.
And before you say it, because of course you will, Halo perfected none of these things. OWNED
...but it did. There is tons of polish lavished upon each gameplay element.
Honestly, I suppose this is something that I like about Bungie. They focus on the core gameplay and make it work beautifully. Myth - The Fallen Lords WAS one of my favorite RTS titles back in the day...and that was a result of its focus.
I really enjoy when a developer decides to focus on a certain type of gameplay and polish it up to perfection. Games that attempt to do a whole lot, but do none of them well, really don't sit well with me unless they do a WHOLE lot. Deus Ex is one of my favorite games of all time, but its individual gameplay elements are so flimsy.
I suppose I should say this...
Regardless of what you think of the game, it IS different. It may use elements from other games, but the overall package and design is simply different!