I don't know that this is uncommon in fiction, but I enjoy seeing characters in jobs involving social work, caretaking, or customer service- anything associated with a "heart of service" or a love of people. I've seen several nurses and teachers in fiction, but I'd even like seeing more waitresses and janitors. Good, hard-working people in any kind of difficult, thankless service job make very sympathetic protagonists to me.
I work in a restaurant and meet a lot of fascinating people in the business who give me endless inspiration and fuel for thought as a writer. Sometimes an average stranger- however opposite of glamorous their life might be- has the most interesting and unexpected stories to tell.