To me, the most amazing part of a video game is the way that it can steal you away from the real world in a way that nothing else quite can. A good book or film will take your focus for several hours, but you're still aware that there's a layer between you and the media. A good game blurs that, lets you creep into the game world for a while and experience things you never would otherwise. There are moments of wonder and joy that you can feel from a few hours in games that are simply unmatched.
So please, stop ruining it.
MMOs in particular have gotten bad about this. It's ironic, as the genre as a whole lends itself to people taking a step into another world. But what's changed isn't a matter of systems or mechanics, just a sense of what designers feel are completely acceptable breaks between in-game reality and the real world. It's annoying. So stop reminding me that I'm playing a game, will you?