Tigger_Magic, I'm confused--jfulcer asked, in your opinion, what the OP should have done.
You then replied, "What I would have done: calmly advised the other driver that I was waiting/signaling to pull into the parking space; told him/her that their behavior was inconsiderate. If they choose to force the issue, I would find somewhere else to park."
Alliecats then asked how you would have "calmly advised the other driver", and you then replied, "Put car in Park. Turn off ignition. Open door. Get out & walk to other car. Talk. It's actually quite simple and easy to do."
Then Darrose brought up a good safety point with, "Tigger_Magic....I think that by turning off the car, and approaching the other driver you may be putting yourself into a dangerous situation."
Your reply is then, "True. I was simply answering alliecats question. I would not advise anyone actually doing this; the safest course of action is to avoid a parking lot confrontation (over a parking space of all things) with a complete stranger".
Huh??? You were asked a serious question, answered, and then seemed to backpeddle.
I can appreciate that you don't think it's worth ruffling your feathers over a parking lot space. It's not that I don't agree with that in theory, but I personally would not roll over and play dead and allow myself to be walked all over in a situation like this. I think what the OP did was right on the mark. Now if I were looking for a spot, saw someone getting ready to leave, but made it to the parking spot at the same time as someone else, I'd back down and not push the point, but that's not what has happened in this case. These drivers KNEW someone else was waiting, but they felt that they were somehow better and the deserved the spot. Very rude and to be wimpish and roll over and let "alpha driver" have what he or she wants is a bit too passive for me. No, it's not worth a fight, yelling, etc.
I recently was in a parking lot and was looking for a spot. It wasn't a packed parking lot, but fairly busy. I saw a spot in the next row and I circled around for it. Someone had gotten there before me and I was going to continue looking. No biggy, he was there first. He looked at me, realized that I was circling for the spot and motioned me to have it. I was shocked. I did take the spot and if I had of seen him I would have thanked him for his polite behavior (and asked if he had a son my 17yo daughter's age...

). We could all use more of that kind of behavior and he brightened my day--a random act of kindness kind of thing.
So I'm all for polite, kind behavior. I love to dish that out and it's wonderful to receive. But allowing a borish, rude person to steamroll over me isn't going to happen without me at least acting like I care.
And we all have hot buttons that we'll react to and resist. Your hot button might be something totally different. Funny think is that I wasn't raised to stick up for myself--my mother was passive, but would then rant and rave to her family about a rude clerk, bad service, a driver cutting in front of her. Better if she would have just learned to calmly speak up at the time than to complain so much later.
T&B