I can only speak for myself here, but after such a long week, I feel like spending my Friday evening mindlessly killing things in videogames. Dead Rising 2 was already lined up as the go-to stress reliever for this week, but a new challenger has appeared.
It's a free, in-browser MMO dubbed Realm of the Mad God. You pick a character, jump on a server, and begin furiously killing scorpions, pirates, and other assorted baddies using projectile attacks. In the process of dispensing justice, you'll run into other players, and with any luck will form a monster-cleansing mob.
Special thanks to Niero for shooting me a link to this. Go on, give it a play.