Guitar, Ear Training, and Playing What you Like
When I took guitar lessons as a young teenager I first studied with a teacher who taught me music reading and theory, and it got me off to a good start, but eventually I switched to a teacher who would show me how to play the current pop songs of the day. This was more fun. One day I asked him how he learned to play the songs on the radio, because all the sheet music in the stores was not correct for the song, and it would take months or years before even an incorrect version was issued. He showed me how to figure out my favorite songs. I went home, did what he said, then came back in and asked him to play the solo I had figured out- "Run for your life" by the Beatles. He played it and I thought my version was closer!
The best way to improve your ear is by challenging it, and figuring out song recordings is an excellent way to do that. I show all my students how to figure out records (now mp3's). The tools available to do this today are excellent, and the process is great ear training.