My favorite would have to be IPB

Well i use vb atm but ipb is pretty good but i prefer vb now :)

My personal choice Vbulletin
I did swear by IPB for some years and 4 months since decided to go with Vbulletin and now will never look back it rocks and the mods are endless :)
So my 0.02 VB

My favourite has to be PHPBB, it's free and powerful. I've never had any problmes with it.My favourite has to be PHPBB, it's free and powerful. I've never had any problems with it.

I am a phpBB user. I love to change everything there (install mods and modify the theme beyond comparison). I run 4 phpBBs and they are all different. I install what I need for a certain community and the theme modifying options are awesome for someone who likes to redesign a lot of the themes.

dojo, I personally have seen your work. And I am very impressed, if you took out the powered by phpBB on your forums. I would not be able to tell the forum software. I only hope one day I can code as well as you. ;)

Are they all yours or you're managing (three of) them for other people?

I just use phpBB. Key thing to me is the cost. I hear and read that vB is the best, and I believe that, but I cannot find a compelling reason why I should spend money to get vB. BBS is one of tools for me to make money, and there ought to be a good financial reason why I should use vB. That said, all my boards are rather small, so maybe that's why I don't need vB right now.

Yea same hear the cost of vb is steep for me as well. Plus I just install the mods on phpbb and it works well. Also my sites are small too. Plus SMF Now just seems more complex than phpbb. I have used PHPBB for a couple of weeks now and don't see my self going back to SMF.

Thank you for the nice comments :)

The forums I am talking about are my own. I pay for them, I run them. it's not that hard. Working with the tpl files is a breeze. I just have to design the headers as I want them in Photoshop, slice and code as a normal html page. Cut the code I need and change some bits of code. Overall_header.tpl is the file I work on the most. And the hacks are so easy to install. There are great explanations in the readme files, so even I can install them :)

I used several phpBB mods, and yes, they were generally well-documented. Also there is a unified framework for phpBB mod documentation, so it generally gets easier and easier as you work on more mods.