I can absolutely recommend Turtle WoW. It is such a good classic+ experience: imagine if there never were any of the wow addons but instead the base game got expanded in a meaningful and in terms of Warcraft 3 lore-friendly way. There are new and very well-done zones which were empty before. There are new items and professions without nullifying the existing ones, there are two new races and new race/class combos (to keep close to WC3 lore), there are new dungeons and raids, tons of new quests and a lot of quality of life improvements. You have many options to play how you want: restrict yourself on how much exp you get and play slow & steady, opt in for a built-in hardcore mode, activate warmode to be flagged for pvp or a combination of those. Also, pretty much all classes got rebalanced (some more than others, though) to make more builds viable without altering the game to much (more balance updates are in the roadmap). The dev team is very active and dedicated.