Have a few M&S ones, though I've generally used M&S for socks and a few shirts + machine washable trousers that look like suit trousers - easy smart-ish option for "business casual"
Diesel has been my go to brand for underwear as I generally get my jeans from them too. I did get some Diesel undies from TK Maxx once too, they were OK though they're a bit different/more cheaply made to the ones from the diesel store - the underside didn't have a double layer and the logo was printed.
Picked up a few pairs from Ted Baker too and they've been decent too.
Diesel has been my go to brand for underwear as I generally get my jeans from them too. I did get some Diesel undies from TK Maxx once too, they were OK though they're a bit different/more cheaply made to the ones from the diesel store - the underside didn't have a double layer and the logo was printed.
Picked up a few pairs from Ted Baker too and they've been decent too.