Get DVD's game consol (PS2, GameCube, PS3, Wii, Xbox, Xbox 360) + some of the film titles are avaliable for FREE download! havent tried that yet but oneday i will.
Tesco prices look to be about a £1 a month cheaper (I think run by love film anyway), and you get clubcard points. If you pay upfront there are discounts of 15, 20 and 25% for 3, 6 or 12 months
Unlimited Discs per month
1 DISC at a time £8.97 £9.97w/games
2 DISCS at a time £11.97 £13.97 w/games
3 DISCS at a time £14.97 £17.97 w/games
Tesco Value DVD Rental
2 Discs per month 1 DISC at a time £4.47
3 Discs per month 1 DISC at a time £5.97
4 Discs per month 2 DISCS at a time £7.47
Not sure about Tesco but LoveFilm has regular competitions Currently theres 8 HiDev TVs up for grabs
Anywho if Tesco is the way to go then go there I've not had a problem with LoveFilm, even when i had to report 2 damaged DVDs they instantly sent replacements + included 2 DVDs off my list which i was not expecting
Don't know if they have comps but the service is provided by Lovefilm so returns etc are just the same (Tesco branded envelope but addressed to Lovefilm in Peterborough), never had any problems but hardly use them now.