Ditto, Cyclemeter. It was the fourth app I tried, after Strava, Map My Ride, and somethingsomethingGPS. Cyclemeter is very easy to use and I don't even need a data plan for my iPhone 4s. The GPS records everything. Only downside is I don't get realtime map views when I'm away from home wifi, but the map appears later with my recorded route.

I'm getting enough use from the app to consider getting a data plan for the iPhone just so I can have realtime navigation aids.