I found the industry list to be very helpful in the past and had these two bookmarks:
http://biz.yahoo.com/ic/index.html (link to the Industry Center)
https://biz.yahoo.com/p/sum_conameu.html (link to the Full Industry List)
It never was easy to find in the first place, thus I had to have a bookmark. With the latest platform change to Yahoo!Finance, I rarely use them anymore.
I agree with everyone, please bring the Industry List back!
I don't know if if it's allowed to post a link to a possible competitor, but here's a link to one site with an overview of US sector industries. I don't know if this is what people are asking for.
*Link Removed - See the community guidelines for more information.*