To be honest with you I've found stealth, lockpicking, science, and repair to be some of the most important stats. In fact if you have the Operation Anchorage dlc for Fallout 3 you can gain access to one of the most overpowered armor sets in the game. A Chinese stealth armor suit that acts like a stealthboy when you're sneaking. And with all the sneak attack critical perks you can get it turns into a skyrim stealth archer thing.

I basically try my best to make my character a master of all trades so I can get every secret unique item in each game. That and being able to kill an entire room of people with one plasma rifle shot each is very satisfying V.A.T.S. or otherwise.

Fallout 4 is a little harder to fully max your character on so I use stealth more than anything when it comes to combat.