Argos is still open and if you miss Tandy's shite ....
It's things rather than particular stores for me. Showing my age here but flipping through LPs and later CDs was a large part of my youth - do I spend my tenner on the new Queen album or the new Police one or the new Bowie one?.
If asked to name a specific store then I miss the old WH Smith from when I was a kid - they used to do toys, records, books, magazines (we are even before the days of videos let alone DVDs and CDs)
It's quite surprising how many stores are still around from when I was a kid 50 years ago - Tesco, Sainsbury, WH Smith, Boots - but there are also a lot that have gone - BHS, Woolworth, Virgin, HMV.
I think there is more wastage to come from the retail sector - even John Lewis is struggling and they have a stellar reputation (reckon Waitrose is keeping them afloat).
My favourite stores now are the big book stores which seem to be vanishing (Waterstones on Piccadilly is awesome), big electronic stores, and the larger stores for decent brand clothing like Gant, Ralph Lauren and Timberland. the sort of stuff I like to shop for in person rather than online