I rarely ask questions like this, but I am curious about this. In many ways, the watch is an anachronistic fashion accessory. For those that choose to wear one in the age of mobile devices, I'd be interested to hear the reasoning behind it.
I wear a Casio Illuminator. I've been wearing the same watch for more than a decade, and this is my third one.
As a fashion statement, it is a nod to the popularity of digital watches in my youth, and a rejection of expensive watches. It also has some 'physicist fashion', I think, and as a working biologist, I like to remember my roots.
As a practical device, I often use it to keep time when I am doing experiments and my hands are gloved and typically in a cell culture hood.
I wear the face on my wrist on my right on-hand. That might be a statement as well, but it's mostly a comfort decision.