The age old question! If you live rural and aerial reception is bad then that is not a question you have to answer. Similar if you have tall trees or obstacles to your south which could block the satellite signal. But lets just say both are possible, which one is best?
I personally like Freeview more as it carries a few more foreign news channels which i enjoy.
But the main deciding factor is probably cost and ease of installation. Let's start with the latter. Freeview is distributed through an aerial and coax cable, its easy as you can split the signal anywhere and boost if need be. You also only require 1 cable for recording. Freesat on the other hand can't be split cheaply so it need a separate cable from the dish to each TV point and if you want to record it needs 2. So there would be a lot more work running cables all over the shop. However if you have already cabling in place like in a new built it is a lot less intrusive than you might think. Cost is next obviously running more cables can be more costly but that is not it. Unfortunately Freesat is not a standard when it comes to TV manufacturers, Freeview however is. What that means is you can use just any TV to receive Freeview while you might have to buy a set top box to receive Freesat. And if you have a view satellite points in your house but none of the TV have Freesat built in you are quickly spending a small fortune.