I try to give every airport I travel through a chance. But if I spot a trend, be it by location, or service or "do I really want to be stuck here for x hours", then it usually ends up on my list of Airports to Avoid.
I was supposed to get back home Friday morning at 10am, flying through Washington Dulles. Got off from Greensboro ok but when we arrived in Washington airspace, the fog was too thick. (note: never pick an airport near a coastline where fog or bad weather is a possibility).
I finally got home at 10pm, having been rerouted to Harrisburg (for fuel), back to Dulles where our original flight had been canceled and the only other flight was at 4:50, delayed until 5:20 and then stuck on the ground until about 6:30/7.
To their credit, United Airlines staff on the ground were amazing. Just never going through there again....