A few weeks ago I was transiting Chicago enroute to Europe for the Austrian GP and had a 5-hour layover that gave me the chance to watch a few birds come and go. With my flight being on LOT, I had no choice but to go to Terminal 5 to catch my flight which in turn gave me a great angle of the Southern East-West runways that most international arriving and departing flights use due to the proximity to the terminal.
For those of you inclined, the best vantage point tends to between Gates M13 and M15 due to their angle to the runway which gives you a wide perspective for arrivals and departures. I spent the bulk of the 5 hours there (with visits to the SWISS, Air France/KLM, and SAS lounges along the way). Yes AF/KLM because LOT contracts with KLM for their Business Class passengers. But take my word for it, you can skip the AF/KLM lounge. SWISS is much better primarily because of their food offerings (Oreos!).
Anyway, here are a few favorites from Terminal 5……