Garmin Edge 500 is what I use. I like data, so the post ride information is great. The other thing I like about the 500 is the size, not to big not to small and I can actually read the display without my glasses! There are a lot of options of things you can display on the screen so you can make it as simple or complex as you like. As far as it taking away from my riding experience I would say it doesn't at all plus I can always leave it at home if I want to.
