WoW is the defacto MMO, almost every MMO created after it came out has been influenced by it in some way. Still to this day it is one of the most played MMO's online and has one of the largest brands tied to its name.
Wildstar recently followed many other triple A titles in offering a very well done free to play option. Subscriptions are still available for those diving deep into the game.
Action based combat makes Wildstar fun and fast paced. You can miss with any ability as they require aiming and timing for many to hit. No tab targeting press and forget attacking here, which makes for interactive and fulfilling combat.
The Developers have been careful to avoid pay-to-win, but being a subscriber or paying some real money for in game quality of life perks can be a big bonus, and offer monthly rewards.