Haha, how long have you got? Not sure if they're stupid or just enterprising...
Gorgeous guy living opposite my friend's mum's house (where I was lodging). Would only see him out of the window either very late at night/very early hours of the morning (assumed some sort of shift work) getting in/out of his car, going in/out of his house. Couldn't engineer an accidental meeting at those hours so left my name and number on a post it under his windscreen wipers. Saw him find it, read it, put it in his pocket. He didn't call though, and literally the day after was the first day I'd ever seen a woman with him, so I guess he had a girlfriend and mental, note leaving, women were not top of his list.
Another gorgeous guy working in the office above mine - different company but we shared a kitchen. I could see him coming down the corridor from my desk and so would get up and offer to make everyone in the office a tea (about ten people) so I could spend the next five minutes chatting to him. This went on for months - no one else had ever offered to make all the teas, not sure they worked out why I was always offering. Did result in a short relationship but ultimately we weren't compatible - stayed friends though.
Met a client (again gorgeous, obvs) but he was peripheral to the contacts I had at the company and spoke to everyday and so couldn't really engineer talking to him that often. I did find out their company played in a softball league though. So I set up a softball team at our company and we played in the league - games always followed by the pub. That relationship lasted five years!
Finally, joined new company and met an amazing bloke, that I clicked with, at a management get together in Wiltshire, of all places. But he was based in the Philippines. So, after only about four weeks, I renegotiated my role, to one out of Manila. We've been together 25 years. 😊
I sound mental. I promise I'm not. 😁