I want to ask the following question directed towards NOCs and network engineers.
What is the toughest problem you resolved? Be descriptive.
However, I'm not sure whether this would make the faq.
This absolutely would not meet the faq. To paraphrase a well known gameshow They're only tough if you don't know the answer.
From the Don't Ask section of the faq
You should only ask practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page.
Your question fails all of these tests it's not about a problem that you face. You are asking for a list of things which makes it chatty and open ended. All answers are equally valid and don't cotain an actual solution to a problem. If you read the rest of the don't ask section you'll see that it fails other tests in there too.