For Alliance it's Lok'Modan, Redridge, Darkshore, Felwood, Stranglethorn (both parts), Plaguelands. Somewhere between 3 - 3.5 of these get you to 60 in like a 16 hours /played, if you queue for dungeons at the same time. I recommend dropping everything at 45 and going to Darkshore-Felwood if you didn't do them yet - they are literally the fastest levelling zones in the game right now, maybe only trumped by Silverpine.
If you’re a returning player, consider paying for a month’s worth of playing time—a mere $15—and using the game’s newer Class Trials to see if you still have that spark for higher-level play. While you can also go the “Starter Edition” route for a free, limited romp through Azeroth, you might need a little more than the newbie zones to help you decide whether you want to play through the game’s latest expansion.
Yes. I believe so. It plays nice with most Addons; even many that are out-dated. The only Addon with known issues is the mini-map in Bandit's UI (the rest of Addon works well with this Addon). The issues with Bandit's mini-map are fixable by disabling its mini-map (how to do that https://i.imgur.com/2zl3IEV.jpg) and using Fyrakin's Minimap. I found no issues with Fyrakin's Minimap. I have not testing other mini-map Addons but I assume the results should be like Fyrakin's.
-Gameplay- Gameplay has largely been stripped down to be a shell of its former self. This trimming has been going on for several expansions, but now it's even worse. Classes only have so many buttons which has resulted in very little skill involved in PvE (even PvP is a faceroll for most melee, lacking any sort of depth and decision-making as it's pretty clear what buttons to press in any given situation) and it's become more of a gear check. This expansion gave zero new abilities to classes, only took them away.
These are a genuinely challenging and dynamic way to play. No two are alike, and the A.I. actually does give you some real opposition. Island expeditions are like dungeons, available in normal, heroic, and mythic difficulties. That means you can press into higher difficulties for more of a challenge. Of course, the PvP version pushes everything to the max.
Hopefully, you have a good idea how you want to begin your endgame experience in Battle for Azeroth. A whole new set of content will drop on September 4 when the Uldir raid opens up and the PvP season begins. That also marks the beginning of Mythic+ dungeons in BfA. Even after that happens, many of these tips and strategies for gearing up will still be the best sources of early gear for your new 120 characters.
Tiragarde Sound and Stormsong Valley are both fairly similar zones, but Stormsong is a little longer, meaning that you might not even have to finish it to hit 120. Tiragarde also comes with a bit of a warning. There are plenty of side quests to do in the zone after you finish the story quests. Don’t do them. It’s not worth the time or the experience you’ll get.