Michael Phelps has awesome technique. He is the best swimmer in the world because he can travel through the water with speed, but stay relaxed and controlled at the same time (this is key guys’). There is more to Phelps than his technique though. Check it out in the great article by ESPN.
Michael Phelps article

The only other swimmer I think has rivaled Phelps in technique is former world champion Alex Popov.

Popov held the 50m freestyle world record before the Fastskin suits were introduced. If your a sprinter or a long distance swimmer, Popov is the ideal person to model in your swimming. The video above gives a great explaination of the freestyle stroke.

If you want improve your freestyle technique then I highly recommend securing a copy of Mastering Freestyle Technique here. It’s a fast and easy way to become a good swimmer. I use the exact program with the swimmer’s I coach.