This is list from GameWyrd’s Lost Archives. It’s a user generated list of cool/not cool pairs from the world of gaming.
Cool: Sparkling dice.
Not Cool: Exploding dice.
Cool: A well-drawn picture of your PC with his sword drawn.
Not Cool: A picture of you at a convention in an ill fitting costume with a cheap replica sword drawn.
Cool: A CD with sound effects to create atmosphere.
Not Cool: A CD with a laugh track that you play whenever something bad happens to the PCs.
Cool: When your Dwarf PC beats an Ogre in a bare-knuckles boxing match.
Not Cool: When an Ogre uses your Dwarf PC as a club in a wrestling match.
Cool: Loaning a newbie player some of your favourite dice.
Not Cool: Making players put the dice in their mouth and spit them out to roll it and calling it a “dice pool”.
Cool: Putting an inventive new game on the internet for free.
Not Cool: Making that game essentially 1ED D&D while just changing all the major terms into pig latin.
Cool: Designing adventures on-the-fly.
Not Cool: Having adventures with your fly open.
Cool: A good GM screen.
Not Cool: A ten foot high GM Screen with a tiny gate upon which the players must knock and say the secret password for you to open.
Cool: Cheapass Games.
Not Cool: Dumbass gamers.
Cool: A glowing review by Dragon magazine.
Not Cool: Your financial records under review in the dungeons of the IRS.
Cool: Having a spirit familiar.
Not Cool: Having your spirit familiar exorcised.
Cool: Having your house rules turned into an official supplement.
Not Cool: Having your house rules stolen by an official supplement.
Cool: Proudly lending your GM your prize pair of gold plate d100s.
Not Cool: Your GM using your gold plate 2d100 for a damage roll against you.
Cool: Valiantly slaying the dragon, saving the princess and earning 1000’s of XP.
Not Cool: Valiantly slaying the princess, saving the dragon and earning 1000’s of hate mails.
Cool: Introducing a new player by having the existing PC’s valiantly rescue the new character from the enemy.
Not Cool: Introducing a new player by having them sit on their hands while the existing PC’s discreetly avoid contact with the enemy.
Cool: Buying magic speed powder from the traveling gnome magician.
Not Nool: Buying magic speed