I've been kind of out of touch lately due to work and life, so I haven't thought to come up with any.  If people would like to submit some ideas in this thread, I'll add some new contests.

Bart

A contest for particle effects or scrolling backgrounds could produce some interesting results.

Particle effects? Some game engines don't have particle emitters and particles can be small coloured planes. Unique particle emitters (like for blender) could introduce some fresh ideas. Here is a list,  but you can also categorize contests into 2d and 3d contests (3d assets are being added slowly).

Dinosaurs

Alien landscapes

Alien flora/fauna

Electronics

Shops (bonus if you can walk around them)

rubbish

currency (both real and fictional)

fruits

vegetables

misc items

Dreamscapes

Dreamscape creatures

Ye Olde Scenes

Futuristic scenes

Futuristic items

Real weapons

Fictional weapons

Dice (blender users have an advantage on d20s)

Skyboxes

Dinotopia scenes

Magical, mythical, and marvolous beasts

Noah's ark

Landscapes

Landscape object packs

Bloddy brilliant british objects

Masks

Anthropomorphic peoples

There's a start, I'm sure I can concoct more, but I have things to do.

http://opengameart.org/forumtopic/callenge-suggestion-chiptune-music-remix

maybe?

Contest:

Alltime favorite sets:

Rules:

Everyone choose one Collection of art, the minimum items of the set is 10 you can create a new set and vote for it when your items are not collected at a place.

Everyone has only one vote and every set can only be voted one time.

However everyone can make suggestions as much he want and if other people like it they can vote for it instead of him.

If many members feel that a voted set has not a high quality then it can be voted out,

If many member think that one item is missing but there are no votes left then it can be voted in.

There can be different contests:

monster, avatars, blends, 2d art, 3d art, anime, fantsy, sci fi.

The aim of the contest should be to collect links to the best stuff on oga and the admin should place the result where it can be seen easily also on long term.

Would it be too hard to allow us to setup a contest? I assume the code is all there, we just don't have access to it. Maybe setup a contest area in the forums, or people can start a contest thread, and then lock it after linking it to a voting thread. I might try this since I'm cleaning up my shop today.