Like what, he asked with genuine curiousity. I don't pretend to be a roleplaying connoisseur, but I've seen my fair share of systems. Most of the ones I've seen either have some variation on the damage save mechanic, or the hit point mechanic. In fact, I'm struggling to think of any that weren't conceptually either one or the other.
Damage saves is the obvious example. I admit that a lot of the alternatives involve some form of "health levels," which are technically a hit point mechanic. But the usual number of health levels is so much smaller than the number of hit points, and the usual methods of calculating "damage" so different, that I feel it should be considered a different system, especially since health levels almost always come with death spirals attached.
(I can also conceive of a "paper doll" system, where you track wounds by location, and maybe some overall status modifiers to represent shock and trauma. That would be more bookkeeping rather than less, but could offer a lot of verisimilitude if done well, and a pleasing level of detail for those who like such things.)
I guess what it comes down to is, either you're okay with instant random death, or you're not. If you're okay with it, then it seems pointless to set up a WP/VP system instead of using damage saves or health levels. You're doing a bunch of arithmetic whose only purpose is to keep track of how much "random death protection buffer" you've got left; but your "random death protection buffer" doesn't in fact protect you from random death. Meanwhile, any time you face a damage source that lacks a built-in bypass mechanic, all the old verisimilitude issues resurface.
Myself, I do want a random death protection buffer, since my preferred approach to gaming begins with "Let me tell you of the days of high adventure." As you correctly note, WP/VP offers the benefits of hit points and addresses some of the verisimilitude problems, at a slight additional bookkeeping cost. So it's my system of choice. But crits that bypass vitality are going in a different direction*.
[SIZE=-2]*I have considered the "crits deal 1 or 2 wound points" approach. It's not a bad idea, but in the end I rejected it on GM headache grounds. Because monsters seldom get a chance to rest and recover, the GM can usually ignore the distinction between WP and VP for monsters and just track a single combined total. This is a considerable plus for the harried GM trying to run a dozen monsters at once, so I don't want to make the GM worry about monster wound points if it can be avoided. I think 4E has the right idea on crits--just deal max damage and leave it at that.[/SIZE]