First in-ears I've heard about were Etymotic Research - you can check them out too, but I think they're above the price point you're looking for?
If you have a chance to listen to them in person, you'll love what Shure, EtyRes, and Ultimate Ears have to offer. Many people wonder why they're so much $$$, but pop a couple in your ears and you'll wonder how they get such great sound out of essentially what are known as "earbuds."
The more expensive offerings will have multiple drivers, tuned ports, etc. All situated in your ear and giving you some serious sound.
I've got the E4c's from Shure. I didn't listen to the E5c's simply because I most likely would have wanted them, but couldn't spend that much money.
PM
BTW, they're great on the plane with a PSP. Especially if you have your usual newborn baby behind you not liking the flight as much as you. They seal out pretty much everything around you.