Essential for the 3.3.5 era, this addon calculates a player's gear level to quickly gauge their equipment strength. Healer-Specific Addons

If you want to change everything at once rather than downloading twenty different files, start here.

If you want to replace the entire Blizzard interface with a sleek, unified look, these "mega-addons" are the gold standard:

This patch is widely considered the "golden era" for UI customization because it predates many of Blizzard’s hardcoded restrictions introduced in later expansions, while still supporting robust addon APIs.

A complete replacement for the Blizzard UI, offering customization for almost every element, including nameplates, bags, and unit frames.

And his threat meter doesn’t show threat. It shows time since he last meant it when he said “I’m fine.”

If you don't want a full replacement, these are the gold standards.