And in this modern 21st century day and age, the critical question arises of whether you want a PC TV card to receive analog or digital television broadcasts.
Both types are available from Hauppauge
and their analog tv/radio cards work very well under Linux since
they have the BT848 chip which is well supported by the BTTV driver, providing both tv and radio support.
You should visit the BTTV driver page
for details of the driver for the BT848 analog tv cards, and
for details of supported digital tv (DVB-t) cards.