I have to partially disagree here. I would say my least favorite it the PGA just because while it's a major, it just doesn't rise to the level of the other three. The Masters would be my second least favorite. Sure the course has some iconic holes but only cause it's the masters and not because they would be known by the course if it wasn't a major. Also, it's obviously at the same course every year and the pin placements are traditional. Everybody knows what every putt and every backboard and every hole is going to play like.
I like the Open Championship best because it's played on different courses and they are the oldest most historic courses in the world. However, they aren't always the best test of golf. Tiger won one going away without ever taking the driver out of his bag (or it may have been once in 4 days). A true test of golf should make you use every club in your bag and some of them in creative ways.
The US Open is my second favorite just for that reason. It's setup to be a true test of gold skills. What you call gimmicks are deep rough and tough pin placements. You have to manage your game on every hole, every round. This year you had to pull out big clubs and hit them precisely on 17 and 18. You couldn't lay up (Phil kind of tried that tactic and it may have cost him). If not for 15&16, Sergio played under par on the rest - but those holes tested his skills in ways he couldn't cope. He finished so far out an so far over because he didn't have the required skills in his game to complete those tests. In the US Open you have to hit fairways, you have to hit greens and you have to manage your misses. It's an amazing test of who is playing the best golf. Ball striking, putting, short game, physical and mental fatigue all come in to play. Calling it a gimmick is short sighted.
