Gee, you can buy the Nobles with the best cables for somewhat over $2200. You could buy the 1+2s for somewhat over $1200. Other than that, everyone here has a variety of favorites (for less) and I'm sure you could get a real good argument going about "best." Suffice it to say that most decently-priced iems will be fine. So much rests on the kind of music you listen to, the shape and depth of your ears, where you listen, what you want to hear when you listen, that choosing a best is impossible. You could cruise through the past 20 pages of this thread and see what iems people have listed in their signatures. That might give you some ideas. But just because I tell you that I like the Dunu1000s doesn't really mean much. And a lot of folks will jump on and say, no, your should try x or y. And they will.
Look at the past 15 pages of discussion re what firmwares we are all using, and that should give you an idea as to how hard it is to quantify anything.
There is a thread in HeadFi devoted to quantifying iems, rated by number. Hint: the Nobles are #1.
