I've visited the Wholefood Co-op every few months for the past 12 years or so, and they've always had some interesting things I wanted to buy.
Because it's a big space, the shelves can sometimes seem a little bare but probably still the widest selection of wholefoods (particularly organic ones), and they remain the only place in Leicester I've seen vital wheat gluten flour for sale. They have a pretty good selection of toiletries and household cleaning items. They were the first place in Leicester that I saw selling the sour cream and dill flavour vegan quinoa crisps, and they usually have a good range of vegan snack foods as well as the more to-be-expected beans, grains, seeds, dried fruit, flour etc.
If you are likely to shop there semi-regularly there is a discount scheme where they record your spend and once you reach a certain amount you get money off your next shop. They also give a discount if you buy a case of something. They will deliver your order if you live locally (deliveries are every Sunday), for free if you spend over £30.
Cons: Stocks some frozen meat and canned fish, Location not central