If it is something the other person has no control about, such as a physical feature, a quirk that is an ingrained part of their personality, or their laugh....you need to learn to live with it.
What would be the purpose of telling someone they have an annoying laugh? People can't change how they express joy or humor. All that would do is make that person self-conscious about feeling and expressing humor. I personally just try to stay away from any type of criticism unless it is solicited in a self-improvement type way, and then it needs to be done with compassion, lots of positive reminders, and a true concern for the other person. It isn't my job to tell other people what is wrong with them, I have enough of my own faults to deal with.
On something like a laugh, people laugh how they laugh. Either learn to live with it or move on, but don't pick someone apart for something they have no control over.