on TDT you can get around 30 digital channels.it does depend on which tdt transmitter you are using...try www.tdt.es and input your postcode and you can see if you can get tdt and which channels.
you can change to the alternate language on most of the main channels (TVE1,2, Ant3, Neox N, La Sexta, Cinquo, Quatro, SET, Disney, K3,300, (some of these may be local channels and you may not get these!), but note that this may not always be english..and the service may not always be available - one channel has the second audio soundtrack as the music soundtrack!
an 80cm dish will not get you bbc or itvs but you can get around 150 uk / english tv channels...many of which are of shopping channels. you can get true movies (and the other variaions) sky news, bbc news, bbc radio, a few music video channels...
this is a cut and paste from my site
What channels can i get on what size dish?
(I am using links as these will be more accurate and complete than posting all the 100's of channels here..)
using this link for free tv channels
http://www.flysat.com/tv-uk.php
on an 80 cm dish you should be able to pick up most of the channels on eurobird 1
on an 80 cm dish you should be able to pick up most of the channels on astra 2,a,b south beam
on an 80 cm dish you may not be able to pick up the channels on astra 2,a,b north beam
on an 80 cm dish you should be able to pick up most of the channels on astra 2c
on an 80 cm dish you will not be able to pick up of the channels on astra 2d