I'm going to skim the Community Wiki aspect first and get that out of the way - if you decide allow these, don't put Community Wiki in the equation. The issues inherent with list questions are not really about the reputation earned - its major impact is on votes, and Community Wiki doesn't do anything about votes. So if you allow these on the grounds you want to show these off, then people should reap every benefit they get from contributing.
My personal recommendation, in line with how it generally falls across the network, is that you shouldn't allow these questions asking for a list. Recall that your purpose as a site, moreso than anything, is to help people and improve the internet. Your means to accomplish this is by providing solutions to the problems users have.
The solution to a list question is a complete list of all the items that could possibly apply to the author's needs in an expert manner. This is something that has never really been successfully accomplished with how these list questions play out.
This isn't to say that these kinds of questions can't be adapted here. The trick is to change their focus so they can be solved. I'll take the examples from Justin's answer of what questions could fit, and show a simple conversion to change it from "Give me a list of options" to "I need a solution".
what are good examples of colored buttons that work well for elderly users?
Let's instead try something like, "How should I design colored buttons geared towards an elderly audience?".
where can I find examples of "sorry, there was a server error" pages that minimize user frustration?
This is easy to change to "How can I minimize user frustration in server error pages?".
what are examples, other than Bing, of putting search results inside search autocomplete popups?
This one might feel off a bit, but I'd go at least in the direction of "How should I design the output of search results inside search autocomplete popups?".
This kind of transformation may seem like it doesn't change anything, but it changes the things most meaningful to the site while retaining the ultimate goal. We allow multiple answers on the very grounds that, sometimes, there isn't just one single great answer. Sometimes there are multiple solutions. So when someone asks a question where there is more than one possible answer, then it will attract those answers. In these scenarios, I've changed the question from simply seeking examples to more asking about the approach. This would allow your answerers to not only teach the theory behind good UX design to solve those problems, but still allow the full freedom of displaying examples of that theory.
The parallel to how it works on Stack Overflow is simple to understand. If you want to accomplish something, and probably want a plugin or script that accomplishes it, you don't ask for a list of scripts to try and suss out the best option. You ask about the problem you want to solve with the script, and in the end, if the best answer is a script, it will come as such. And, likely, it'll be fleshed out into an awesome result that your readers will like to read. If it gets upvotes, it won't be because it's merely some item that people like, but it'll be because it gets the desired job done.
The answers you get will come in the same flow as you would perceive a list question. But the founding difference is that you can have a conclusion to such a question. Even if more answers may come, a single answer can solve the problem posed by the question, allowing the author to bring closure and allowing future readers to see this as a solved problem. That's what users want to see - they want results. So focus these kinds of things on the results.
Not all lists can be transformed like this into a usable question. But these also tend to be examples of stuff which you would not want to see.
