As of when I stopped searching religiously about 3 years ago, I had two complete sets of Jefferson from circulation (1938-1959 anyway) and close to a few more. I have at least one roll (40 coins) of most of the series. I think I am only missing the 1938-S and 1950-D to complete the next 3 or 4 sets. I believe the next lowest totals were the other semi-keys (1938-D, 1939-D, and 1939-S).
I believe I also had around 45% of the buffalo nickels and 30% of the V-nickels from circulation.
And since other denominations were mentioned, I am 1 coin away from completing the Franklin set and 2 coins from completing the silver Roosevelt dime set (1946-1964) from circulation. If I remember correctly, I also have 30% to 50% of the silver Washington quarters, walking liberty halves, and mercury dime sets from circulation.