The Daily Grind: What's the one feature you can't live without?

So some assorted systems in MMOs, so little time. From crafting to combat, PvP to PvE, housing to sieging, some MMOs offer a panoramic difference of features to their players.

Yet, there's always that digit feature that rattling makes us love our mettlesome of choice. It's that digit abstract that we every read on the back of the box that rattling lighted our imaginations and made us follow the mettlesome on the furniture and pull out our wallets. Today's discourse is quite simple: What's the digit feature that you can't springy without in your MMOs?

When you narrowing it down to one, throw it into the comment box below and deal it with your fellow readers. Now, discuss!