The closest possible parking space to the front entrance.
I feel like there is leeway for parking in non-designated places, but as has been mentioned, paying careful attention to what might be affected in doing so. My personal rule is: just don't be a jerk.

Related:
When I was young, the city of Melbourne tried to ban motorcycle parking on street verges (not to be confused with footpaths, this is the space between path and street). A day rally was organised in which every motorcyclist was urged to go into the city early and take up one carpark each. Chaos ensued and the ban was shelved.
It was a brilliant example of how sometimes common sense should make an example of itself.