← Amsterdam Marathon
One of the flatest races out there (but by no means completely flat - there are some minor bumps); but also a very popular race which means it gets very busy and overcrowded in places. I wasn't a fan of the smell of smoke (not just tobacco) around the central areas, or the diesel fumes along the Amstel section.
The start and finish are amazing in the stadium however, and due to the time of year you've got a reasonable chance of great running conditions.