I too am a huge fan of the in-ear style, so much better in the audio department in both clarity and loudness. Also, every design that i've tried with an in-ear gel has been way, way, more comfortable during extended use than any of the on-ear ones. Some people find the in-ear gel to be "uncomfortable" but i think that's mostly due to the fact that it feels weird. Once you overcome that odd feeling, then you're good to go for hours of continuous wear. With the on-ear ones, i find that while it doesn't feel as weird when you first try it out, once you've been wearing it for a while you actually start to feel pain on the ridges of your ear that the speaker is resting on - it goes beyond annoying or weird, and becomes downright painful (again, my opinion, maybe i just have sensitive ear ridges ).

a tip for finding one you like: buy one at a big box retailer that has a satisfaction guaranteed return policy. When i was shopping around for one last year, i literally tried out about 5-7 headsets at best buy by purchasing one initially, then returning/exchanging about once a week until i was happy. sure, you can always find cheaper prices online, but once you buy it, you're pretty much stuck with it. in the end, i landed on a wired headset because i'm too picky.