Do guys wear wristband on the left?

It doesn't matter, personally I usually wear mine on my left wrist. But sometimes if it bugs me then I just wear it on my right wrist, and I am also right handed.

I guess it depends on the person, where ever it feels comfortable then it can be worn, or if the person is left or right handed. So it doesn't matter which wrist you wear it on, you pick what is comfortable, or preferred by you.