My bugbear is "Chat" threads posted in "AIBU" (turning it into Chat II). Sometimes this is deliberate "for traffic", but it's also been mentioned that it can be accidental when newbies land on AIBU from a Google search for MN and don't realise there are other sections. This has been partially addressed by the addition of a drop-down menu to show other sections, but would MNHQ consider also adding a prompt? So when someone starts a thread, where is says "Topic", could something be added to that asking people to actually chose the most relevant one? eg "Topic - please chose the correct section from the drop-down menu".
Yes it's minor, yes I have far more important things to worry about, but it's one of those little irritations that makes using MN less enjoyable meaning I have breaks from it