dead heat between the banjo minnow and the helicopter lure...
actually, for freshwater, the simple, time tested rubba worm has got to rank up in the top 2 (zara spook or jitterbug being the other)
for saltwater, gotta go with the jig and pig...(i think that sluggos will rank right up there, but they've only been around for the last 5 or 6 years)...