>is the best antagonist in the franchise in your path
Seriously though, the trilogy really suffered from the fact there wasn't a proper concrete villain for the player to go up against throughout each of the main games outside of 1. ME2 was too busy being coy about Harbinger/Collector General to bother making them feel like an actual character, and he had zero presence in 3 to the point you wonder why he was built up at all. The Illusive Man flip-flops throughout 2 on being morally grey or outright villainous, and despite the game's best effort at depicting them otherwise, he and Cereberus come off as incredibly incompetent, having to rely upon Shepard to fix their constant mistakes. They even make a joke about it in the Citadel DLC. Compared to Saren, who was always shown being one-step ahead with numerous resources at his disposal that he actually uses effectively throughout the story.