yellowsix

Again, thanks, that worked! Sort of. HOWEVER,  I had to tweak it to make it work. You said that the gettrigger_r function returns a value from 0 to 65535. this did not work for me.The values that actually allowed the right trigger to function were 0-255. At first I was getting no response from the controller with the default value you suggested of 20000, so I set the gettrigger_r value to 100, pulled the trigger almost halfway, and it worked. Setting that number higher than 255 and the controller will not respond. Or maybe I did something wrong to make it act that way.

And now for a super silly question.... while I can now sprint with the R trigger, the L and R triggers are still giving rumble feedback depending on how much the triggers are squeezed! I can't find where these functions are being called to disable them!

Oh, those were the values for the force feedback functions, my bad. Trigger values do indeed go from 0-255.
As for the rumble code, if you started off using the example as a template, the piece of code that binds the triggers to the rumble function is in the step event of the obj_xinput object. Try removing the following piece of code, or at least the setrumble part:

// Set controller rumble
for (i=1;i<=4;i+=1)
{
    if plugged[i]
    {
        left=gettrigger_l(i-1)
        right=gettrigger_r(i-1)

        setrumble(i-1,60000/255*left,60000/255*right)
    }
}

Well, Halo's PC version was after all a direct port from the XBox. (which was done terrificly, in my opinion)
The game was lagging behind because it's a game released in 2001. The PC version came two years later when Gearbox ported it.
Though it's gameplay felt indeed different than other PC shooters, I actually liked the controls, and it's campaign was, imho, definitely superior to most other FPS games around the time.

The global.__rightTrigger variable is a reference to the DLL's function for acquiring trigger information, not the actual trigger value. You can obtain the information from the right trigger with the gettrigger_r function. This function returns a value from 0 to 65535. The higher this number, the further the trigger is pressed.
You can check if this value exceeds a certain threshold. If it does, the player is pressing the trigger.

Try substituting the example you gave with the following:

if keyboard_check(vk_right) && gettrigger_r(0)>20000
{
        move_contact_solid(90,8);
        move_contact_solid(0,8);
        move_contact_solid(270,8);
        image_speed=1.2
}

If you feel the trigger isn't responding good enough or too quickly, you can adjust the '20000' in above expression to change the threshold.

Alternatively, you could make the image_speed variable scale with how far the trigger is pressed. This way, the player can control precisely how fast the character should run:

if keyboard_check(vk_right)
{
        move_contact_solid(90,8);
        move_contact_solid(0,8);
        move_contact_solid(270,8);
        image_speed=1+.2*(gettrigger_r(0)/65535);
}

That should do.

In other words, I'm not a "hater" (I actually quite like it) but I have to say that it isn't a game that "revolutionized the gaming industry". Sure, it set the standards for online console gaming, but it didn't "wow" everyone.

I do agree on that, and I must admit that certain critics have severely over-hyped the series, calling it the game of the decade, and whatnot; which is terribly far-fetched. I would say it's one of the better titles music-wise, though.

Possibly Duke Nukem Forever.
Definitely the Halo series.

*edit*

And all of the games that I said I would make

I don't get everyone's resistance against the Halo series. I ordered Halo 3 a couple of days ago, and I'd go ahead and say it's one of the better multiplayer games you can get your hands on for the 360. Besides that, the campaign is pretty rad too. Sure, the commercials surrounding the franchise were a bit too much, but the series definitely made an impression on me, especially when you take the music into consideration. The only part I found disappointing was Halo 2, which had a rather dull campaign and music tracks by Incubus and Breaking Benjamin, which in my opinion don't really fit the game.