Health is the most worthless to dump skill points in to. This I is because you can go to the hospital and completely refill your health every 45 seconds. If you are attacked by other players, (unless it is from a hit), they can no longer hurt you once your health drops below 20.

The only place where more health helps is in the boss fights in the game, but as there is no special reward for completing the boss fights and there are bonus items you get from doing jobs to make the boss fights easier, you don't need more health. Finally, most of the time you are logged in, you will want to keep your health as low as possible to minimize the number of fights lost, so it is highly recommended you never bump your health.

It may seems a high health will help you survive better if someone puts a hit on you, since if your health was high enough, you could heal every 45 seconds and never be knocked out. The problem with this theory is the hit never goes away until it is completed. You will have to sleep eventually and then that huge pool of health will just turn into a huge number of lost fights before you are inevitably knocked out.

Since there is no defense from a hit and no way to get it cancelled, you are better off just dying in as few fights as possible so the hit gets cleared and you are back in the "protected" health range of 0-19.