One would think at first encounter that the FR scheme of interlaced conversations would be quite confusing. It is not so. The human brain can apparently follow parallel conversations quite well.
I still find this forum the easiest to follow and use of all the ones I either belong to or visit.
The Bulletin Board variants like our sister site, free Dominion, aren't bad, but their "paged" format makes it easy to miss things- here, you just keep scrolling to find stuff.
Probably the worst are those that use nested folders, like a sentence diagram-- I go stark starin' Cuckoo trying to follow conversations on those.
The chatrooms with live chat- seems like our Yahoo! fallback site had one, once-- aren't too bad once you jump in them, but I've never been very good a chatter.