I guess I'll offer my 2 cents because I've certainly been engaged in a few of the aforementioned threads...
1) The biggest problem I see is with reposts. An example of this was the numerous Sander Sassen threads going on about the same topic. They were all flamewars (which was really ok given the nature of the topic IMO), but there was too many of them. Mods should have locked each repost quickly. By reducing the number of redundant threads, it will allow people who want to avoid a topic to do so easier.
2) There needs to be more sticky FAQ threads at the top of the forum, specifically, a rundown of ATI's and NVIDIA's cards (seperate threads) with links to benchmarks. There are very few legit video questions and almost 2/3 of those are "which card do I get if I want to spend $200 to play a few games?"... I would love to be helpful, but I get tired of answering the same damn question everyday. These FAQ threads could probably answer most people's questions unless they have some sort of special situation. Additionally, having the threads stickied would make it easy to point a reposter in the right direction, as opposed to making me search for the dupe thread for them. (I think it's only polite to give someone a link if I pull out the repost card.)
3) Then there are the "joke" posts. If your original post is supposed to be a joke, include a disclaimer. Don't wait until 4 pages later to state, "wow, you guys don't have a sense of humor" (this thread is a nice example of that). Personally, I like a bit of humor, but if you start a new thread, I will give you the benefit of the doubt and take you seriously. While we're on the subject of jokes, if someone has already posted a link to a satirical site they made and you make another one, don't start a new thread about it, add it to the existing one.
4) Mini Mods won't work. I have quite a pretty extensive background in mitigating network abuse, and giving people who are not accountable to the owners of the site "power" is not a good idea. It sucks for AT, but they have this forum here for the ad revenue, and it's their job to keep it up to a certain standard... There is no "free ad money". It's their site, they should moderate it. If they don't want to and it gets the point where it is unusable, people will stop coming.
5) This a suggestion really... People should use the many forums on the web for different purposes... There is no perfect "one-stop forum". AT is great for getting the latest info because someone on here is always checking out the inq or hkepc looking for new info, and it offers some great discussion on these news items (sometimes they involve flamewars, but at least there is generally good participation). On the otherhand, AT video IMO is a poor place to go to get genuine help with problem resolution. I had a few issues with my SLI rig and I opted to post questions about them a nvnews because of the potential flames. The downside for me was that nvnews has a lot let traffic then AT, so I didn't get nearly as many responses as I would have here, but none of them were flames either.