I think the subject has been covered many times. However, if you have and outdoor aerial, and most communities have, depending on where you are you will get about 70 or so channels but only about 8 to 10 of them will have the dual language, These do include the Disney Channel! You will also get American series such as Bones, CSI (all variants), Hawaii 5-0 and comedies such as Friends and two and half men etc and MTV plus a couple of other Cartoon channels. Also a fair sprinkling of films (and fairly modern ones at that). Yes, it is worth it to get a TDT box. Does your TV not have a built in digital tuner? Most of them have if the set is less than 5 years old and all TVs sold in Spain have one. if you can put up with the amount of adverts then TDT is fine.
Note, you will not get a news channel on TDT in English. Have you checked with your neighbours or the president? They may have a lead or be able to lend you one and you can have a look round the ferreteria or one of the Chinese shops to match it up.