I rather like No Quarter Magazine- Privateer Press' bi-monthly magazine supporting Warmachine, Hordes and the Iron Kingdoms Roleplaying game.
About two years ago, they started having a painting competition in each issue, and every painting competition had a different theme and different rules. Some months are extremely competitive, and others are less so, based on how much interest this particular challenge is.
Here is my warjack that won the "Riddled with Bullets" competition- the idea was to make a warjack look extremely damaged, but still fighting. From the look of the two runners up, this one was a very competitive prize.
He's one of the few competition quality minis that I have on my website right now. After doing him, I'm convinced I'll do a whole Magnus the Traitor force with this battle damaged look on all of them.