Capturing Good Audio: What Do You Use?

I'm yet to shoot anything serious with my equipment, but all i have is a Rode Videomic.  In my tests, it seems to be adequate both indoors and outdoors, though it misbehaves under windy conditions,

Am i wrong to put all my audio eggs in this basket?  Someone suggested that i should by a few wireless lavalier mics and a mixer, but I decided to pass because they are rather expensive.  Was that a mistake?

What would you say is the minimum one should have to be able to capture good audio in most situations?