Well, I am going to say GOT Pro, because I love GOT Pro.
You will find that there are huge fans of both games, and both will defend the one they like.
As for why, the rules on GOT are a blast. There are a lot of ways to play it, and you have the ability to switch things up along the way. The mini wizard mode (Hand of the King) is fun, but I find it difficult. I haven't been to the Iron Throne mode, but others have. I enjoy playing it a lot, and sometimes the scoring possibilities with the multipliers can get nuts. It makes you decide if you want to make the shot you need, or try and increase the multipliers first.
As for TWD, I've played it a bunch, but it never clicked with me. All of my play on the newest software has been on location, and the game is constantly full of cheap drains. I don't find it fun like the brutality of Iron Man, but instead just unfair. This is much worse on location with a tight tilt. It is a constant nudge fest to try to save balls, which leads to lots of tilts and frustration on location. Maybe some day it will click for me, but it hasn't yet.
BUT, because they both have their fans, I would still venture saying that they are both excellent games. Just because I don't like TWD doesn't mean it is a bad game, it just doesn't fit me. But GOT does fit, and man, that game is a blast.