In Cheshire: as far as I know, D&G Bus still operates free services from Offerton, Hazel Grove, Poynton and Bramhall (service T2) and Knutsford, Mobberly, Wilmslow and Handforth (service T3) to Tesco at Handforth Dean Retail Park, though I can't imagine this will last particularly long. Handforth Dean in the past had a free service from Cheadle as well - that's gone, and there is now Stagecoach route 42C, though that of course charges fares.
T2 operates on Tuesdays and Fridays with three services per day in each direction, and T3 on all other days (except Sundays) with one service per day in each direction.
I doubt it still runs as Tesco got rid of all of their free bus contracts last year (and Asda got rid of all of their free bus contracts the year before) so if it is still running than that means that it would be running without any funding from Tesco which i think is highly unlikely. I remember contacting Tesco via email and they confirmed to me that every Tesco free bus route in the UK was being withdrawn. So although i can not find any evidence online that the Handforth Dean free bus was withdrawn i think it most likely was last summer when they withdrew all of their contracts. Unless of course this is an exception and they have decided to keep this one running for longer.
From reading other posts above in this thread and doing a bit of research online i believe that these are the only remaining supermarket free bus services:
• Coop - Hove - Go Ahead Brighton & Hove
• Coop - Oundle - Dekker Bus
• Marks & Spencer - Torquay - Stagecoach
• Morrisons - Penzance - Williams Travel
• Morrisons - Pool - Williams Travel
• Sainsburys - Bognor Regis - Compass Bus
• Sainsburys - Chichester - Compass Bus
• Sainsburys - Crawley - Compass Bus
• Sainsburys - Harrogate - Connexxions Buses
• Sainsburys - Littlehampton - Compass Bus
• Sainsburys - Newport - New Adventure Travel
• Sainsburys - Team Valley - Go Ahead North East
• Sainsburys - Watchmoor Park - Stagecoach
• Waitrose - Newark - Travel Wright
The one to Coop at Oundle may well have already been withdrawn but i am struggling to find anything to 100% confirm this. The one to Waitrose in Newark is being withdrawn next month in April as confirmed above.
Also as mentioned by someone else in an earlier post Compass Bus (Asda in Crawley) and Go Ahead South Coast (Asda in Poole) still operate the Asda Free Bus services as commercial services that charge normal Single fares and Return fares but as it is mostly OAPs most passengers still travel for free.
Feel free to correct me if you know of any other ones that are definitely still operating.