Special mention is the Darkmoon Faire Top Hat and WHEE! buff. While not always available due to the DMF being inaccessible most of the month, if you happen to be leveling when the DMF is running, it might be worth your time to go and get these. AFAIK they do stack with heirlooms, although I have not personally tested it. Fair warning: These buffs do NOT stack with each other, and the hats disappear after the DMF goes away later in the month(unless you only log in when the faire is running).
The game guide to the World of Warcraft Battle for Azeroth is a handy set of practical advice and guidelines that will help you in getting answers to the most important questions about the new expansion. Battle for Azeroth is the latest expansion set to the much-loved MMO game. Since its launch the game has collected great reviews and everything indicates that Blizzard has delivered another exquisite in-game content for months to come.