9. Syrio Forel
HBOThough physically diminutive and unimposing, the former First Sword of Bravos is easily one of the finest swordsmen in Game of Thrones; able to make up for his unimpressive strength with pure technique, speed and footwork. We just see Forel instructing Arya Stark in the combat style known as water dancing for the majority of the first season though even against this limited opponent it is all too clear how skilled the instructor is. Water dancing foregrounds the importance of speed, footwork and balance to make the great swords and heavy armour of Westerosi warriors seem sluggish and ineffective. We finally get to see the Essos warriors abilities against someone other than his young student near the end of the first season as he single-handedly holds off Ser Meryn and a unit of Kingsguard cronies for long enough for Arya to escape, using nothing more than a wooden practise sword. It is heavily implied that Forel is eventually killed in this skirmish but his ability to hold his own with little more than a stick is still extremely impressive. He may be small but underestimating Forel based on his size is a huge mistake. The ex-First Sword of Bravos is an exceptionally talented warrior despite being one of the few fighters in Game of Thrones who we never actually see kill anyone.