What in your opinion is the most versatile lure: can be used shallow, deep, slow, fast, winter, summer, spring, fall, pitch/flipping etc.?
IMO it has gotta be the ole jig 'n' pig. You can use just about any trailer depending on the style/speed of your retrieve. It can be fished fast, slow, in deep water, and shallow water.
For weight, i would say that the 1/4 oz- 5/16 oz sizes are best. I like 1/4 oz best for year-round, all types of water fishing, but 5/16 is better for the deep stuff.