Depends on your budget but im under the impression beyer dynamic cans are very good for monitoring. Their 250s,770s and 990s are supposed to be superb. expect to pay around £85-125.
I'm using Sennheiser HD570's. A good pair of cans for comfort over a long period and I think they're good for sound quality too.
Problem is, whatever headphones you wear, your ears become desensitised over a mixing session. It's better to do a bit and then walk away for 10 minutes, then come back to the mixing. And when you've got it finished - leave it until the next day when it'll sound completely different again!!!
I use mine when the neghbours are in - you mean you play around with music when your wife's in?
