As others have said, the BL03 is unbeatable for the price but the cable is crap and it will pull them out of your ears. Alternatively and my #1 pick would be the KZ ZS10 Pro, I've only had my set a week and I'm really impressed. I didn't get the one with the mic, but I believe it's only a £1 more to get it with a mix cable.
Starfield seem to be well regarded, I've not listened to those but was going to get those instead of the KZ, glad I didn't, the KZ are shockingly good and I would wager are equal to plenty of the big brand multi driver IEMs. I've never heard those footsteps at the beginning of Lady Madonna on the Love album sound so clear, better than every set I own and have ever listened to and that's one of my test tracks including Maxine from The Nightfly.
