Best Chat Module for Drupal 6.x

But I remember reading about a lot of issues that were caused by phpfreechat. A quick look at the issue queue shows that there are tons of open bug reports.

Have you checked if there are any reviews on druplamodules.com?

I use phpfreechat and it does work (had to use a couple of workarounds from the module's issue queue, but after that it worked fine). Also tried chatroom-- simple, but it works as well.

FlashChat is the best. Integrates perfectly with Drupal 6. You can see it at my site:

http://bf1942.ath.cx

i've been testing bowob or realchat, both of them need an external chat server. I think chatroom is simple, clean and offers the best performance for chat rooms and even sound alert. In didn't need videochat nor features from phpfreechat. Maybe chatter is another good option

I just want to mention http://drupal.org/project/tribune, since I don't see it in your list.
I'm the author so I won't give my (obviously biased) opinion on which module is the best :)

I haven't tried all of them, but chatroom is simple and doesn't require any external services or downloads.

One of my clients asked me a few months ago about adding chat to their site. I looked over the available options at the time and ended up deciding that Chatroom sounded like a nice, simple solution. Installed it, tested it, everything seemed pretty decent...

But then once it was opened up to their users, the complaints started coming in. Apparently people have had all kinds of problems with it -- posts not showing up, people getting spontaneously dropped out chats they're in or not being able to join in the first place, etc. And this wasn't even on a particularly high-traffic site -- there were only ever a few people using the chatroom at any given time. The module just seems really buggy and unstable. Hopefully it will improve eventually, but right now it really doesn't seem like a good solution.

So, I'm going to be trying out some of the others. I'm wary of PHPfreechat since there seem to be a lot of complaints -- I suspect it would just be more of the same bugginess. Tribune seems to have mostly positive reviews so far, but I don't know for certain if it will do what they need (allow small groups of students to start their own chats to discuss collaborative class projects) -- it seems to be geared toward having one big chat space for everyone, but I'm not sure. I'll be trying it over the next little while and see if there's a way to make it do that I need.

There really doesn't seem to be one standout chat solution for Drupal at this point... Hopefully someday there will be.