Over the air - Digital HDTV PVR any recommendations?

I am looking for a decent over the air HD TV – PVR. I am looking to get rid of my current cable provider and use only over the air broadcast, but would still like to record shows as I do now. If possible I would like it to be able to record two shows at once. I would also prefer not having to build anything. Do you have any recommendations? I would like to connect it to my 50” Samsung plasma.