To balance out the previous post :)
I replaced my Hifiman RE-0's! They're a very very good sounding earphone for moderate money. To me they sound very good, but with little bass so some people may not like that. But the biggest selling point is they sound as good or better than earphones that cost $300. They were about $85, but you can get them cheaper online.
I got my first pair a couple of years ago, they had some problems though. The cloth covered cable was constantly getting knotted, and also if it dragged over your shirt you would hear that in your ears. It had a small plug which was quite fragile and that's the part that eventually died on them. Also back came off the earbuds, that was because the helmet tried to rip them apart every time I took it off, but this was fixed with sandpaper and superglue.
However the new ones have fixed two issues at least and they come in different packaging now. The cable is now plastic coated, and the plug is now much chunkier. I'm yet to test the durability with my helmet. I think they also sound slightly better now too.
I got them from Munkong Gadget. They have two outlets that I've found so far. One in Digital gateway (go out the opposite side of the Siam BTS station from Siam Paragon) and another in Pantip Plaza (on the ground floor, towards the back, head right and it's near the Bangkok Bank branch that's hidden away there). Small store, but they had a good selection of headphones and amps.
I went to get these because the Logitech headphones I got in Cambodia were excellent fakes but sounded horrible. The box, the pamphlets inside, even the earphones themselves all looked right. But they sounded just like any other boring earphone, nothing like what the reviews said about them and no where near Hifiman territory. The box was missing a few things which I saw in photos on some reviews so that's why I figure they were fakes and not just bad sounding headphones. So I stuck with a lesser known Chinese brand instead of going for another big name brand that's probably going to be a fake anyway.