What are your favourite forum packages?

I have none in particular because I love a lot of forum packages for different reasons:

XMB Forum - Not being worked on anymore and support for themes/mods is completely dead since 2 years, but it's still a strong forum software which you could use for a lot of things. A lot of the themes are quite ugly but most other things are implemented extremely well.

MyBB - Successor to XMB, although some things are better, some things aren't as good, unfortunately. I find it can be clunky for some things at times.

phpBB - Best for large and professional communities, my hosting forums run phpBB3. Solid package and very secure overall.

My own site runs XMB Forum and used to run MyBB before I decided to change it and start fresh after someone said the look was kinda professional. It doesn't work with PHP 7 though but minimum works with PHP 5.2.x. Me and LKRJC plan to contribute to XMB development and mods in time.