These are the top 5 essential addons for Vanilla World of Warcraft / WoW Classic that we simply can’t live without.
VanillaGuide is a step-by-step in-game leveling addon based on Joana/Mancow’s famous leveling guides. This is by far the best in-game leveling addon for Vanilla WoW and is great for players who want to level to 60 as quickly as possible. It also has built-in profession guides!
KLHThreatMeter will show you how much threat you (and other players) are generating so you know how to adjust your damage to avoid pulling aggro off of the tank in a dungeon or raid. There are many good threat meters out there (for example: Omen Threat Meter), but we like KLHThreatMeter due to the customization options available.
Mail is a quality-of-life addon developed by shirsig (who also authored aux, which is a Vanilla auction house add-on similar to TradeSkillMaster). Mail will let you automatically open all of your mail quickly and auto-complete names when addressing mail. Absolutely indispensable for players who frequently use the auction house.
HonorSpy is pretty incredible in that it does a relatively accurate job of estimating your current PvP rank and predicting how your rank will change next week. It does this by automatically inspecting players near you and creating a database (that syncs with your guild) that is used to crunch the complicated vanilla PvP rank calculations.
DPSMate is hands-down the best damage meter for Vanilla WoW.