[attenuated 3db]

Or you could go the custom audiologist-fitted route:
 
 
http://www.etymotic.com/customfit/index.html
 
Personally, having only paid $80 for my MC-5s, it's hard for me to rationalize spending $100 for custom-made eartips, but the MC-5s (and HF-5s, obviously) qualify for the program.

 

[mark2410]

buy a pair of small olives, they work wonders

 

[SteeleW]

It takes a little while to become accustomed to the deep fit but your ears will get used to it. I use the tri flange tips with mine because I found that they sounded the best. You just need to wet your fingertips and use that to moisten the tips you are inserting and put them in with a twisting motion. The isolation is second to none.

 

[imackler]

I really like the Klipsch gel tips: http://www.klipsch.com/na-en/products/exclusive-oval-ear-tips-overview/

 

[yliu]

Quote:

etymotic's isolate better than any other IEM.....i have tried them all,nothing else comes close....must be a tip issue or you simply arent inserting them properly

I think the Klipsch Image X10 rivals Etys in both isolation and comfort.