I allowed stress from a former job to enter a previous relationship. It wasn't pretty and I learned a valuable lesson. I don't bring it home anymore. I'm starting to feel really stressful about my current job, not because I don't like the company (awesome benefits and opportunities), I'm just really bored with my current position (I've been in the legal field for TOO LONG). In lieu of taking it out on love ones, I'm channeling that energy into outside activities that make me happy.
I think the worse thing you can do is to bring it home to someone that doesn't understand what you are going through. There's a difference between just talking about your day and beating someone else down with your issues. That's why its nice having friends in my field of work. I can bitch & vent and not burden a significant other or friend.