SPOILER ALERT!!! READ NO FURTHER IF YOU AREN'T CAUGHT UP ON GAME OF THRONES
Euron is a newer character in Game of Thrones, the uncle of Theon Greyjoy (Reek) and Yara Greyjoy. He is essentially a pirate and has recently captured Yara as Reek fled in fear rather than save his sister. He is attempting to woo Cersei Lannister and has been making it a point to take jabs at Jaime Lannister as he tries to get in bed with Jaime's sister, who happens to also be his lover. He is a brutish, evil bastard and is making enemy after enemy.
My theory is that it will either be Cersei or it will be Jaime who kills Euron. Jaime out of anger and/or jealousy and Cersei out of dominance and strategy, or potentially as a show of love for Jaime. I don't believe he'll survive long (maybe I'm wrong), but what are your thoughts?