As a pax I've experienced three go arounds.
One, going into Miami, was due to the fact that our plane got too close to the plane in front (the captain came on and said this).
The other two were in Singapore and were weather-related, something that doesn't seem to have cropped up on this thread. In Singapore -- and throughout SE Asia -- you get intense squalls of wind and rain which affect air operations.
One of the go-arounds was actually a touch and go! We had to land at the alternate on Bataam (Indonesia) and I got the ferry back home!