There are 58 films available in this deal, as part of the 3 films for £15 but if you use BEST10 voucher, you'll get 10% off, making it £13.50 for 3 films including delivery and if you go through Quidco, you'll receive a further 5% cashback, making it just £12.83, that's under £4.30 per film including delivery :)
I won't list all the films, as i don't want this post to be too long and want you to check it out yourself, as there will be some films that others may like and i may have a missed some gems but these seems to be the best ones i've spotted.:
The Ring Two
An Inconvenient Truth
Napoleon Dynamite Collector's Edition
Failure to launch
Get Rich or Die Tryin'
and many more