Have heard (in order of preference):
SM3, Radius DDM, FX700, Monster Miles Davis, IE8
Want to hear:
JH16, EM3 Pro, SE535 (just slightly curious), Fischer Audio Eterna (a budget IEM which is on par with the IE8's is intriguing), maybe the upcoming FutureSonics Atrio (new driver is about to be released- will need to gather opinions on the change in sound though), and a few others I'm sure I'm forgetting.....
But shy of trying out the two customs listed, I'm pretty darn content with the SM3's. Those who've listed them in the want to hear, do yourselves a favor and give them a try.