Working from home seems to be a bit of a cheat, but that means my dress code is very simple. Usually shorts, T-Shirt (in summer) add a pull-over in winter. @Max- maybe another topic for a slide show? Maybe not...
Max, I tend to go with a suit, nice shirt and tie. In fact it is a little annoyance of mine that engineers in the UK want to be seen in a similar standing to other professionals (Dr, Lawyers etc) yet seem to think the it is OK to turn up to work scruffy looking.
Max, I'm tracking your progress 10 years ahead - UK engineer in the 70's, Germany in the 80's, Silicon Valley 1986-now. Plessey Radar 1973-78 was proper trousers, shirt 'n' tie, and sports jacket. Even when I split to do contracting, I kept that momentum. MBB was the same, but here, beginning at Nat Semi, anything went, and still goes. Management wearing jeans for most of the subsequent startups. But for some reason, despite the complete lack of peer pressure, I still prefer dockers to jeans or shorts. Probably nostalgia.
We've come a long way in dress codes since the great engineers of yore like Brunel and Eddington, with their dress coats and wingtip collars. And since everything is cyclic, I'm just counting the years until the full wig makes a comeback.
HDD/SSD test/development lab/offices:
I wear jeans or khaki pants and polo or button up shirts (I don't tuck my shirts in) and casual brown or black ESD shoes. Some wear shorts in summer. Some wear a bit dressier slacks and tucked in shirts. No one wears ties except maybe on a special occasion.
Business-casual here (Drexel University). Polo shirt and khakis in the summer; a button-down shirt (no tie, no suit, thankfully!) in cooler weather. Perhaps shorts would be allowed in summertime, but my own personal dress code doesn't allow that, at least at work.