The "teardrop" shape is pretty good, though the name is a fair bit misleading as droplets almost never look like that. Their shape varies in time depending on the flow conditions.

Not quite sure what you mean by spindle shape, but I'm sure a variety of shapes like that could be pretty good. For the front, it's important to not have a flat tip. For the back, you'd want a gradual decay of the radius to prevent the fluid from separating off the back, creating a large wake. These are the heuristics.

Which shape objects have minimum drag is a fairly interesting subject. The shape with minimum wave drag (i.e., supersonic flow) is known, but I'm not sure there are any general proofs for other flow regimes. Perhaps it doesn't matter much, as we already know a bunch of shapes with low drag. The real problem seems to be getting these shapes adopted, as (for example) cars don't seem to be bought on rational bases like engineering. This should not be surprising.