Aside from RRF, mylespaul.com is another minefield. Some of the spats I've seen on there are pages long (search for the Joe Bonamassa gin meltdown) and some of the plonkers over there are not adverse to hurling and insult at you out of the blue, as is a particular Moderator who is frightfully rude and clearly unstable, both on the forum itself and in private messaging.
TDPRI, a Telecaster forum, is pretty friendly, and if you inadvertently cross a line you're politely warned via PM, often with a smiley as an accompaniment. But, RRF and the official RIC forum were scary places to inhabit at times, esp if JH was on the warpath.