This of course excludes people who work in video game stores. For the rest of us I find it to be a nice treat to see retro video games at work. I work in film production and this is where I've seen them.
At the telecine lab (film transfer). They had a Sega Genesis hooked up in the lounge. I didn't get the chance to look at their games but someone was playing Sonic
At the editing suite. They had a Genesis, Super Nintendo, and a Turbo Graphics. Nobody was playing them but I saw them neatly arranged under the TV in the lounge.
In my office of course although this doesn't really count since my office is home. I have my Super Nintendo hooked up next to my desk so when I have to wait for things to render I can play a quick game of Pilotwings.