I voted TiVO, but only because I have the DiSHTV TiVO wanna be. Not nearly as cool as TiVO, but still LOVE IT.
Can't record one and watch another (unless you're watching something you have recorded... then you can also record something else). Can't record two at the same time either (which would make sense with the previous statement)
CAN pause, rewind, FF etc.
It truly is a cool toy