I decided on a NordicTrack C2050 treadmill due to the reputation of the company and the following features:
Where you can run on this treadmill, I would not say that this model is the best for running.
I've had my treadmill for about 5 years and have yet to have it repaired. I've only had to adjust the belt once to tighten it.
If you are looking for a beginning treadmill, I would recommend the Nordic Track C2050.