It really depends on what you are using the camera for, will you be taping other hunters or trying to self video?

The GL2 is obviously the newer version of the GL1 so I think the choice between the two is a no brainer, especially if your buying new (GL1 is no longer made).

As for the XL1, if you ever plan to self video it would not be a good choice as there is no LCD screen on it, just an eye piece and even though you could buy an external LCD screen for it I don't feel it would be practical for hunting uses. That being said, if you plan on only taping other hunters the XL1 will give you a better quality video, but may be more camera than you need unless you are planning on producing a show or DVD for resale.

Also why are you limiting your choices to these three cameras? If you are lookingfor a good camera for low light , you will not be happy with the XL1 as low light is not the best with this model, in SD the Sony PD170 is one of the best low light cameras, I would also look at the Panasonic DVX100b as it is a great camera for the price and has the biggest LCD screen of all the cameras listed (great for self taping).

At any rate don't forget about a quality shotgun mic. to go with your camera as audio is just as important as video.

Good luck!