There are plenty of stand-out performances in Game of Thrones, and most of the best characters only seem to last a season. Ned Stark and Oberyn Martell come to mind, with the latter being portrayed perfectly by Pedro Pascal (apologies for the alliteration there).
Pascal's career really seemed to take off after that, something that he admits in an interview with Vanity Fair. "The role that changed my life was in Game of Thrones," he said. "I will always credit its creators for taking a chance on someone who had nothing but unknown theater credits and episodic television on their résumé. I still awe at the opportunity that was handed to me by David Benioff, Dan Weiss, and Carolyn Strauss. Without Thrones, I would not have had Narcos, The Mandalorian, or The Last of Us."
Compared to the father-figure role he often gets today, Pascal's time as Oberyn was spent quite differently. He was a bit of a playboy in Game of Thrones, first being shown inside a brothel, and yet he was also one of the deadliest combatants we'd ever seen by that point. A shame he loved showboating a bit too much.