Blockbuster have a pay as you go option and a "Unlimited" dvd rental subscribtion.

Free 14 day dvd rental trial as standard, but enter code:"ST65447"  possibly receive an extend trial to 30 days.

enter code "XZTP56" for 2 Months free trial (thanks to Laz)

• Blockbuster : Pay as you go
  keep your rental DVD(s) for 5 nights,
  New release DVDs £4.50 to rent for 5 nights and other DVDs are priced at £3.50. But if your going to rent more then 3 new release dvds a month a better option is blockbusters "unlimited" packages.
  
  
• Blockbuster : Package deals:
  Rent up to 3 DVDs at a time  £14.99 a month.
  Rent up to 5 DVDs at a time  £20.99 a month.
  
  
• Get a chance to buy ex-dvd rental dvds from £4.50 with free postage and 30 day guarantee
  
• Blockbuster  Customer Services:  0845 60 60 383
  9 a.m. to 6 p.m.  Monday to Friday
  Post: FREEPOST Blockbuster - (dont need no stamp this is not address to return dvds to)
  
  Email : onlinestore@blockbuster.com
  
• Payment: Switch, Mastercard, Visa, Delta , Visa Electron.
  
  
• Return address if you lose DVD envelope:
  FREEPOST (SCE15059)
  Bradbourne Drive
  Tilbrook
  Milton Keynes
  MK7 8BR