The Screwdriver is vodka and orange juice. That's it. The vodka is there for the kick and stays out of the way; the orange juice is the drink. So the orange juice is where your effort goes. Fresh-squeezed makes a better Screwdriver than any vodka upgrade you could buy, and it isn't close.
Spend the money on oranges, not vodka. You'll taste the oranges.
History
The name shows up in print by 1949, in a Time magazine dispatch from Turkey describing American engineers drinking vodka with orange juice and calling it a screwdriver. The story that oil workers stirred it with an actual screwdriver is a great story with no evidence behind it.
It took off in the 1950s and 1960s as vodka itself took off in America, sold as the spirit you couldn't smell on your breath. A neutral spirit in orange juice was the perfect pitch for that. The Harvey Wallbanger is a Screwdriver with a Galliano float on top, which tells you how standard the base had become by the 1970s.
The Spec
Two ounces of vodka, five ounces of orange juice, a highball glass full of ice, an orange slice. Some recipes go 1:2. With fresh juice I like it longer; with carton juice, the shorter ratio hides less and you'll notice.
The Juice
Fresh-squeezed navel or Valencia oranges, strained if you don't like pulp. Three or four oranges gets you there. If it has to be bottled, pick a not-from-concentrate juice from the refrigerated case. Shelf-stable juice tastes cooked, and vodka can't fix that.
The Vodka
Any clean, unflavored 80-proof vodka. Tito's, Smirnoff, Stolichnaya. This is not the drink for a $50 bottle. The orange juice will flatten the difference.
Bottom Line
Squeeze the oranges. Everything else is a rounding error.