We're considering moving our documentation to a wiki. I tried the SharePoint wiki but it seems really poor on features. Then I tried Mediawiki, but we don't have PHP/MySQL available in our network. We work a lot with Microsoft technology and I was wondering what is the best Wiki that you used that is written in ASP.NET using MSSQL?
I agree, the Sharepoint Wiki is horrible. I'd go so far as to say it's about the most un-wiki-like wiki I've ever had the horror of working with.
DekiWiki is good, though some of our users commented that it seemed a little "Fisher Price" for them (i.e. it looks a little too much like a toy and not a real site). Obviously custom themeing could resolve that, if it's a concern.
Telligent recently released a wiki for Community Server, but I have not had the opportunity to install or review it.
I suggest you look at ScrewTurn Wiki. It is free and source is available for it. I use it for many purposes and have really enjoyed it. The performance is top notch.
Taking Cori's answer above and bringing it current, MindTouch has done a lot of work on the wiki component of their platform. There are several other reviews on this site that talk to it's strengths and weaknesses - but it's hard to argue w/a free trial.