Definitely possible, I’ve got a Technotrend card and a DVD-T card.
I prefer the freeview one to freesat. After scanning I had hundreds of channels to edit through (all the skye subscription channels and every single regional channel as well). However… It also lets me watch F1 with out having to subscribe, simply tuned it into RTL for the visual and I have a radio tuned to BBC4 (I think off the top of my head).
The main brands seem to be Hauppauge, Compro (my freeview card is a Compro and a friend has a Hauppauge one), both work fine with Media Centre. Unless its for a laptop, try to avoid a USB one.
Pay attention to the type of card you get, DVB-T is freeview and DVB-S is freesat. If this is followed by a 2 ie DVB-S2 then its capable of receiving HD broadcasts, but the DVB-T2 cards seem to be very hard to get hold of.
Most DVB-T cards are both analogue and digital, this then allows you to connect other things ie a skybox or dare I say it a good ole video player.
