This quote from the excellent Perdio Street Station by China Miéville sums it up perfectly
"There were three of them. They were immediately and absolutely recognizable as adventurers; rogues who wandered the Ragamoll and the Cymek and Fellid and probably the whole of Bas-Lag. They were hardy and dangerous, lawless, stripped of allegiance or morality, living off their wits, stealing and killing, hiring themselves out to whoever and whatever came. They were inspired by dubious virtues. A few performed useful services: research, cartography, and the like. Most were nothing but tomb raiders. They were scum who died violent deaths, hanging on to a certain cachet among the impressionable through their undeniable bravery and their occasionally impressive exploits."
This basic idea makes up part of my house rules too.
In my old school games (Swords and Wizardry, B/X or Labyrinth Lord ) rather than average folks in extra ordinary circumstances, i.e. 3d6 straight across or arranged as desired, roll for hit points, I've always gone 4d6 arrange as desired ,max HP at 1st level and "Greyhawk Average" (middle number on the die+1) thereafter.
Characters made this way are tougher than most starting characters but not so tough they unbalance the game. Plus having an edge is part of what I consider fun. I don't really want to spend my extra time pretending to be ordinary when I do that every day.