OK. You didn't qualify price point. So here goes.
The BEST solution is from Sensaphonics:
http://www.sensaphonics.com/?cat=10 They make silicone custom molded head phones and also make custom molded sleeves for Shure musicians monitors.
Impressions from an audiologist will cost about ($50-75)... well a doctor appt. Get a hearing test while you're there have insurance cover it.
Then the headphones are $450 - 1000.
Now the sleeves are cheaper... $150. Shure SE315 ear buds are $200, so $350.
Here's the advantage: they fit PERFECTLY. You can wear them ALL DAY. You can block out 100% of outside noise at whisper quiet volume. (plug your ears and hum - you get the idea). They are good for lawn mowing.... in the gym.... on stage (why I have a pair).
Downside - on the street - you cannot hear ANYTHING but music and your footsteps.
So... this is the BEST solution.