Naveen Andrews has been in Lost for four seasons now and it is clear that he is one of the most complex and intriguing characters in the show. Naveen Andrews is certainly one of the mos talented actors in the show and his performances in nearly everyone of his episodes is stunning.
In the season 2 episode, One of Them, Sayid comes across a man caught in one of Rousseau's traps and believes him to be one of the others (first appearance of Ben Linus as well, good times). Whilst questioning the man in the hatch, he lets his anger boil over and gives a heart breaking speech about how you would remember every moment of burying the woman that you loved. It is a well timed and well controlled performance which makes the viewer under stand his character on a deeper level.
He also gave a great performance in Solitary, Collision, Enter 77 and The Economist and with his character being one of the Oceanic 6, here's hoping he will have plently of episodes to come.