Here's a few of the memorable things they've helped me with over the years:
1. While on a UA ticket, on UA metal going YYZ-ORD-MEM, when my bag missed the connection and last UA flight of the day, the AC concierge in ORD found my bag and put it on an AA flight for me that night.
2. In YOW, I was arriving to meet my family to spend the weekend there. My wife was arriving before me by 45 minutes or so, with baby, stroller, lot's of carry on. The YOW concierge met my wife at the gate, grabbed a few bags, and escorted her and baby to the MLL to wait for me.
3. In ORD, I've been met on arrival at least twice I can remember by the ORD concierge, where the concierge had a chocolate, a smile and let me know where my connecting gate was.
4. In YYZ, the domestic concierge office let me drop off a box of catalogues on a Friday night, that my E status boss was picking up Sunday morning for a trade show he was going to.