We're going back to bottom bracket school!
There are two measurements for bottom brackets on most current bikes.
The first is the actual bottom bracket shell measurement. On mountain bikes, the most common is a 68mm English thread bottom bracket. That's the most likely bottom bracket that you presently have. There are two other bottom bracket shell you might come across on other bikes, namely a 70mm Italian thread or a 73mm English thread.
The second measurement is the length of the spindle. This varies greatly, and different cranksets require different lengths. This measurement also affects your chainline, so if you're looking for peak performance from your drivetrain, you might want to look for a bottom bracket that allows for adjustment of the chainline. This can either be a threaded adjustment or through the use of spacers.
The LX crankset will almost certainly fit your bike, as will all of the other cranksets that have been mentioned.
I'm also researching cranksets for my bike and at the moment I'm leaning toward a Race Face Atlas crankset. The Race Face crankset is more expensive than the LX or Hone, but it does have one advantage. You can order just the arms and install just a single speed chainring instead of having to throw out the extras on the other full cranksets; and that will to part of the way to getting you a better crankset for not much more money.
Tom