HD Camcorder Compatible with Mac?

I am planning on purchasing a MacBook. I am also planning on purchasing an HD Camcorder, and I want to make sure that it will be compatible with Mac Software. I have read that when transfering videos onto a Mac, sometimes video quality is lost.

Does anyone know if this is true, or if there is any way I can avoid losing quality. Are there any particular camera makes/models that are better for Macs?