I watched Bangkok Dangerous today. Most reviews I've read give a bad review on it. I think it's actually quite entertaining and what I'm going to write contains spoilers so be warned.
Most shooter movies I've watched usually involve the shooter missing a target or being blackmailed or framed and runs from everybody - friends, law enforcement agencies, anti-law enforcement agencies. B.D. however, is about the main lead running from himself.
There are several interesting plot developments in this film, from teaching a student on killing, to dating a girl who is deaf, to the price of life. It explores rather contrasting elements, from warmth of a cold-blooded hit man who only has four rules in life, to the touch of a deaf girl. In a particular scene, the lead gets mugged as the girl walks on in front, unaware of what that's happening behind her. He however turns the tables and shoots both the muggers. Several blood drops spray onto her coat, and she feels it, touches it and turns around to see the guy she likes holding a gun and two dead civilians on the ground.
The movie also challenges the rules we make for ourselves. The lead has always worked alone, and has left no trace behind. This time, he has a student, and he has to rescue the student. A rather interesting scene was where he had to make the decision to shoot a well-liked politician or not. His student told him the subject was a good man. And for a moment it seemed every person he aimed his sniper scope at was smiling. Thus, the mental battle raged. Rules or goodwill?
A lot of subjects are actually gently prodded in this movie, and blink and you might miss it. While the suspense building up to the ending was a little swift, and there were scenes that seemed improbable, overall, this movie is actually quite watchable and easy to understand, though I would advise you not to watch it from the third row from the screen. Unless you have a very very flexible neck and body that can conform to the shape and angle of the seat.