Where is a nice place to live in SF (or nearby) for a 40-something single male professional?

I have lived in the South Bay my entire life and am currently exploring new jobs. Depending on the location of the company where I will join, I am looking for a change of pace; I definitely welcome a location with a professional, neighborly vibe, but also welcome peace and quiet since I telecommute and take calls from home from time to time so I am probably looking at either a 1BR or 1BR with den that I can use as a combo living room/office.

Still trying to figure out my budget, but I ideally don't want to spend more than $4,000 per month for rent, utilities, parking and other essentials (e.g. food, Internet, etc.). If my numbers are off, please let me know -- always happy to be told if I am over or underestimating my numbers.

Did some research already and found a few neighborhoods in SF like Noe Valley, Hayes Valley, Pac Heights, Richmond District that look appealing as well as maybe renting a place in Pacifica (the non-foggy part :)).

Thanks everyone!