I'd like to echo the recommendation of Bon Marche. I buy their stuff and have done for years. For my own clothes, I don't keep anything in my wardrobe that won't survive a vigorous full 40degree wash followed by tumble drying on full heat, and all the Bon Marche clothes I have bought stand up to that. My only reservation is that I've found their jeans shrink a bit so they're not very thorough with their preshrinking of cotton, but their slacks are great and I've been happy with their tops, although they do often go in for ones with holes/sequins/buttons etc. that may not be so suitable for communal washing, so if you're buying online, look at the picture carefully to make sure any patterns are just machine-embroidered.
I also endorse M&S. I always think you know where you are with them. I don't buy their trousers so much these days because the shape doesn't suit, but I buy other stuff there and I've never had cause to return an M&S item on quality grounds. On the other hand, where I've bought items for Dad and got the size/pattern etc. wrong, they've taken them back with no quibble at all. Over the years, I've seen a lot of M&S stuff in charity shops and I don't think it's because people don't like it, I think it's because they gain/lose weight before it wears out.