Altorin said:
or 4. which I see most of the time, is "turtle until I lose".. or the "Hope for Allied Victory"
Lols if they do that, they've lost already in my mind.
The most important part of a proper turtling strategy (and I probably should have mentioned this) is knowing when and where to expand to, and when to go on the offensive. When you expand to a new resource zone, do so deliberately and install defenses there. They don't have to hold off the whole world, but they just have to hold long enough for reinforcements to arrive. Perform regular reconaissance, and adjust your plans accordingly.
I think it's also important to note that turtling doesn't necessarily mean staying exclusively in your starting zone. it just means picking your expansion points and fortifying them heavily. If someone turtles but doesn't leave their starting area, then you're quite right; they will most often lose. However, that's an indictment of the player not the strategy. I play defensive, and in many cases I win. I'm not super-badass, but I do well enough to think that turtling is viable.