LG HBS750. (I'm on my second pair, upgraded from HBS700.) Comfy, you can use them in one or both ears when you want, you can answer phone calls without having to pull out the phone, pause/resume, adjust volume (standard Bluetooth features), and they are almost impossible to lose by accident. 8 to 10 hours of playback on one charge. They do let in a fair bit of wind noise, so I often have to pause, especially when riding into headwind.
Looked at Jaybird Bluebuds, but they look like they might slip out of your ear and end up on the pavement after the first pothole unless you keep both buds in ears or both buds out (they lock to each other magnetically on your neck when not in use.) Even my HBS750 buds occasionally fall out of the ear (more often when running than when biking), but when they fall out, they just dangle off the collar till you pick them up. As pointed out above, it's technically illegal to ride with earbuds in both ears in CA, but it's permitted to ride with an earbud in only one ear.
On the other hand, Bluebuds are considerably more compact, which could be a plus. They are also supposed to last 8-10 hours per charge. Their buttons are much smaller, out of necessity, not sure how inconvenient that would be in real life.