I suggest the following voting system:

Difficulty (How hard is to solve it?)
0 = Not rated
1 = I can solve it with my eyes closed
2 = For children
3 = Not too difficult
4 = Hard enough to make it interesting
5 = You need to be really good to solve it

Creativity (How good and original the idea is?)
0 = Not rated
1 = You call this "idea"?
2 = The author is good in the art of Copy&Paste
3 = Not the best idea but still interesting
4 = Nice one
5 = The author is really good

Presentation (How much effort did the author put on this?)
0 = Not rated
1 = The author should be shot
2 = The author was lazy
3 = Just enough
4 = Nice, well built and explained
5 = The author is an artist

Education (How much can someone learn from this?)
0 = Not rated
1 = Nothing new, and not interesting at all
2 = Nothing new, but it makes you remember some things
3 = You can learn things from it or to solve it
4 = Interesting, good stuff on it to learn
5 = I had to become a master to solve it

Liked (How much did you like this challenge?)
0 = Not rated
1 = I suggest it should be deleted
2 = I wouldn't mind if they delete it
3 = Normal
4 = I liked it
5 = I want more of these

There's also in this thread a nice idea from someone about adding a new checkbox in "My account", checked by default, with the text

• [x]Want to compete

People with that item unchecked wont appear in the ranking but they still can solve challenges, write posts in the discussion afterwards forums, ...
For me it sounds interesting. What do you think about it?

Yep, thats a nice voting system Phas!
Im down with that.

Cya,
Darkego

Hum... I have to say there are really interesting ideas.
Since I don't really write often in the forum (the hint system for pvcuong ) I'm going to concentrate my thinking in this post :

1 - Challenge submission
It must be standardized (see previous posts).

2 - Rank or not rank
Add a new checkbox "Want to compete" in "My account" checked by default. So everybody will get the choice and it will be the end of this childish war.

3 - Voting system
Phas' voting system seems to be good, but what about the "liked" part ? Will it be the base used to delete or not the challenge ? If so, what will be the limit ? Maybe if the average mark is lower than 2 the challenge should be deleted...

4 - Challenge evaluators
I really don't like that idea ! How to determine if a user is active or not, if a user is able to be an evaluator ? Who will decide it ? I think it's to give too much 'power' to people. This site is really great and its community also. Don't break this spirit. Ask others what they think is really good, but decisions must be taken by admins. Too much people to decide will complicate things. It's in human nature. I really hope I'm wrong thinking that but...

So, another idea about that : maybe we can just keep on uploading new challenges and let people play with them. Then, two ways :
- at least (for example) 20 users solved it in less than one month, or
- one month but solved very few times
If 20 users solved it or after one month, a script checks votes and decide if the challenge should stay or be moved. Yes, I say "moved" because I think also that deleting 'bad' challenges is not a good idea. Why not just move them in another category (called bin if you want) where those who didn't get the time to solve it still can play with ? These challenges will not increase your ranking. It will be just for fun, or to learn new things, or to increase your skills, ... Maybe the 20 first users who solve it think it's not a good one, but maybe others won't think that. And don't forget the one who submitted it : maybe he really spent a lot of time to create it.

It's just my feelings. Now, it would be great to take a decision because that's a lot of work for admins and we all know they don't have a lot of time...

Well if you need 20 solvers in one month you can almost remove all crack-its and CONTACT would be removed as well.. I don't think that is a good solution. With the correct description of the challenge + solution, I think the admins should be able to evaluate the challenge (according to a list of questions). Challenge evaluator are an option here.. they form the moderators of a forum.. but I don't think these moderators or admins should compete, since they simply have inside information which no-one has.

Anyway, you also have to rate the current challenges as well and remove the useless.. even if lots of people solved it.. live is hard and nothing is ever easy.

Another thing I just came up with.. if you set the solving time to one month then you will have to adjust that time during holidays etc...

How about this.

Besides the votes -which will just give general info, not info which will decide deletion- use the polling system which is due to be added soon.
Add a standard poll-question to the vote page à la "Does this challenges has to be deleted?"
And 2 option buttons. "Yes" and "No". (Optional a textfield could be added to allow to voter to comment why he/she thinks a challenge should be deleted,
this feedback is readable for the challenge creator and for the admins who care (so they have free choice to read possible spoilers)).

Everyone (who solved) gets to poll!

The outcome of the Polls will be shown in the voting page (like the other votes) and will be an indicator for the ADMINS if a challenge should be deleted.
Please read it that I said it should be an indicator for "Challenge Deletion" for the admins to decide on, not a automatic deletion script.
The time to act upon a poll for a challenge is up to the admins and based upon the voter-comment-feedback.

Any feedback on this?
Greetz BaRa!

PS:
For the ones who don't understand what I mean.
A poll is a like a voting system, but you don't get to vote on a scale how much you like something but you get to choose what you like, eg:
"Which challenge category is your favourite?"
o Stegano
o Programming
o Crypto
o ...