The fire is more versatile then the nook so if you went with a tablet you might want to consider the kindle instead although the nexus something (I forgot the name) has a comparable option that is supposed to be fantastic as well.
I honestly don't know how comfortable any tablet would be for watching tv though. Unless you have a set up like dish network that lets you watch on any device you are going to be relatively stuck with a few shows.
On the other hand you can definitely use the tablet for searching the internet for whatever your needs are.
Personally I use my tv more in my sewing room and use my laptop when I need to search something.