Within that budget: Klipsch Image S4's (or the S5's if you want a rugged pair for outdoor use). Can also purchase S4i's if you want iDevice controls or S4A's if you want Android controls. I have the X10's and they are wonderful but well out of your price range
Believe it or not, my new fav <$100 IEM are the Monoprice 8320 (MEP-933). They're only $7 ($5 sometimes), but are the best price/performance IEMS I've listened to. They work well for all types of music. I enjoy them with metal as much as electronic/rap.
Monster Turbines are decent and are usually under $99. IMO I would stay away from the Klipsch Image S4 unless you like sibilance. If you can up your budget a little the Ultimate Ears TripleFi 10s are better than both of these. My current favorite is Sennheiser IE 8s, you can buy refurbs for around $200. I own all of the above IEMs.