Zombie Apocalypse
It depends on the archetype. I'd respond completely different to classic Romero-style slow zombies than I would to 28 Days Later style rage zombies.
Against slow zombies, I'd prefer some tough clothing (at least leather jacket at all times, and full-body suit of motorcycle gear when I expect trouble), a good melee weapon, and open ground. The real danger in a Romero-style scenario is getting trapped. The only thing they can do is outnumber you, and that only means anything if you hole yourself into a situation where the only escape is through the horde. Stay mobile and avoid congested areas where you can be ambushed. You can easily outmaneuver them and whittle away at their numbers. If enough people do this, it shouldn't take long to put down even a large outbreak. If you need to rest, choose a place with more than one exit, and arrange in advance for a diversion to clear your escape.
In a fast zombie scenario, I wouldn't have much hope. You would have to barricade yourself into shelter and just outlast them. For the longest time, I had determined that I wouldn't even try if something like this happened. Then a friend of mine made some really good points about how different pockets of survivors barricaded into shelters somewhat near each other could coordinate to make good things happen. Shelters take turns drawing all the zombies to them, while the others do whatever they need to do in relative safety. A lot of stuff could be done like this. Or you could even just run the buggers back and forth in their insatiable rage stupor until they collapse.
Of course, all plans assume that people don't make really stupid mistakes or malicious decisions, which is how things always go wrong in the movies anyway.