The Skeleton Rig:

Here it is, over five years of work (off and on).
The aim was to create a rig that was as easy to animate as possible but still give as much control as possible.
In my opinion - for the amount of control you have, this is probably the easiest rig to animate with in 3dsmax.

Version 2.x Features:

Full IK/FK blending on the arms and legs.

A simple yet powerful spine setup with independant hip rotation and adjustable chest influences on the head and FK arms.

Squash and stretch parameters on the head, chest, arms and legs along with adjustment for how much thickening and thinning the bones do when squashed/stretched.

All limbs can be easily bent into curves with options on the style of curves made.

All limbs have twisting and volume preserving bones to greatly help deformation.

FK and IK snap buttons for the arms and legs and automatic hiding and unhiding of IK and FK controls depending on the amount of IK for each limb.

Finger controls with preset poses that can be altered as a group of attribute sliders and/or as rotation of the bones themselves.

Character pipeline tools for adding extra mesh objects to the rig, adding a prefix across all of the rigs' objects, an assume skin pose button, select all and delete all rig objects.

The rig also contains manipulators. These are not like max's standard manipulators, but are objects that you move instead of going to the modify panel and adjusting a slider. With the manipulators, you can pose the entire rig almost any way you wish using only the move and rotate tools.

Lastly - and maybe most importantly - in my infinite benevolence I have created a script that will resize the rig to whatever character you may have... as long as they're bipedal. You just load the rig file and set the script to be a hotkey, toolbar button and/or menu item. From there a simple interface will let you resize any part of the rig you wish. It also lets you mirror one side's sizes to the other and even specify the number of twisting bones in the arms, legs, neck and spine.

...plus other little things to help make animating easier.

Note: The rig requires Paul Neale's attribute holder script for the fingers (for 3dsmax 6 & 7 and 3dsmax 8 & 9 ).

Version 2.x Demonstration videos: