No Lego Love?
The poll is problematic, because I'm sure many like me use a combination of mini types.
Our primary minis for PCs and major NPCs is Lego figures. I've got a slew of castle and pirate legos from my childhood, and they're still making them, so I pick up a few now and then (got some orcs last year, for example). They're ideal because you can pick the perfect outfit, armor, weapons, helmet, hair, accessories, etc. I recommend placing them on a 2x2 or 2x3 flat platform, ideally black to match the D&D minis. Fits in a standard grid with no problem.
I've got a bunch of D&D minis as well, and they are the primary source of monsters and enemies. It makes it easier to tell who are friends and who are foe when the mini types are distinct.
Of course, we've also got glass beads and the like that are always available when we need some hordes or movable terrain features.