I have a few so I'll put them in order. =D
: An anime cake design contest.
I've never done something like this before but it looks like fun. Plus, even if we lose you'll still have a cake right? lol
 Make a Decorative Anime Bento box!
Even if you don't have a bento box you could just use a plastic container. You know, like the ones from the Chines restaurants. You could choose a theme for us and have us dish out our best...ahh...dish.
 Tsundere contest!
The rules would be this: Make a two panel comic strip with two real life photos of yourself. Most Tsundere wins!
 Tea making contest!!!
Anime is what introduced me to tea. =D You could connect it with Anime's like K-on or even "Natsume yuujinchou". The rules would be: Take a picture of your favorite tea in the most Japanese setting. You could incorporate an anime theme into it.
 Clay sculpting contest!!!
Speaking of "Natsume yuujinchou", I think it would be the perfect thing for this contest. You could ask us to sculpt our favorite anime characters out of clay. One per entry.
 Crunchyroll Gundam making contest!
This one might be a little more advance then most contest. You could ask us to take a photo of a gundam model we constructed. To make sure no one cheats and just takes any photo offline, you could make it a requirement to have the Crunchyroll symbol drawn or printed onto a card or piece of paper right next to our models. Winner would be the one with the coolest pose.
 Shadow art contest!
Not to long ago the manga artist of "One punch man" & "Eyeshield 21" made some really cool art using a flashlight and shadows. The contest would be to see who could make their own anime styled art using shadows. A limitation would be that everyone has to be in black and white.
 Paper craft contest!
Just as it implies! ^.^ You can choose an Anime from Crunchyroll as its basis and ask us to compete by making paper crafts of set Anime.
 Anime nail design contest!
You can pick a Crunchyroll anime as its theme and have us design one or both hands of nails for it. This one isn't necessarily girls only. I mean, us guys can participate too...but if you want to save your Shonen Highschool Manly side from the torment of nail polish, you could make it so that the nails can be drawn on a friend or relative like an niece or sister. =p
 Manga collection contest!
Its a simple photo contest to see who has the nicest Manga collection. That doesn't mean "Who has the most". It would be based on more then that like neatness, quantity, display, etc~ To prevent cheating you could make it so that a card with the crunchyroll logo has to be displayed in the photo.
That's all I've got so far. Most are from the top of my head. ~(╹A╹)~
If you liked any of my suggestions pleas use them! I'd be happy to participate in any one of these. And YOSH! Thanks for your time.
(♪)Good Food. (♪)
I think the caption contest is a good idea,but most people don't post a caption. It is hard to come up with a clever comment so they just try to add thier own funny dialogue, myself included.
A four panel comic would be a great contest but then most people would complain that they can't draw, myself included.
Why not embrace the insanity of the current caption contest? Post four screenshots from an anime and let people add thier own dialouge to create a four panel comic of their own making.