I tried many forum platforms, mostly to see what they all offered. I mostly stayed with SMF and later StoryBB because familiar with the codebase and they did what I needed (and in StoryBB’s case nothing else does what that does)
Tried: phpBB (didn’t like the ACP), MyBB (no responsive by default), SMF, Wedge (couldn’t deal with the other dev), MiniBB (no ACP), CBACK (confusing ACP), Flarum (no attachments by default), XF (pretty good, wish there was a better content solution), Invision (expensive, and I dislike the shrinking addon ecosystem), vBulletin (hate the ACP), Woltlab (it’s alright but it doesn’t wow me), Flatboard (dislike how it handles users), NodeBB (I don’t like Node much), Discourse (lots to dislike about management at scale, not to mention it’s in Ruby)
There’s probably some I’m forgetting.