1853 Large cents . . . 1853 seems to be the most denomination-dominant year. See what I did there? I coined a new one . . . Whoops, did it again. Haha, I kill me.
I actually saw a magic trick in print in the mid 1960's that was just to ask someone to take a nickel from their pocket, do some mumbo-jumbo and tell them it was a 1964!!!
'64-D Lincolns were at one time the most common but over the years millions of them have wound up in circulation. Another very common date was the '60-D sm dt. These were hard to find but there were many looking and many saved. None of the later issues are more common than the '64-D was but a few are more common than the '64-D is. A lot of '79 to '83 issues were set aside but some of these are a little tough now because of zinc rot. A penny was very little money in 1979 so a few people set aside a lot of coins. Who knows how many are still around but it is probably substantial. There were a whole lot of bicentennial quarters saved as well: Probably in excess of 20,000,000 though Gems are hard to find and a lot of these are lightly circulated now days. If memory serves the '60 sm dt was a $2.50 coin in 1975. The '60-D sm dt was 25c, and the '70-S sm dt was $2. Today they are $1.60, 2c, and $40 respectively. That's a huge drop on the '60-D.
As far as LWC's found in the wild, the three most common ones I encounter are the '44, '45 and '56-D. If we're talking pre-'37, it's the '19.......hands down.
I agree. All too often I have my 1960 hat on and, like you, those older than mid 30's were most often 1919.
Most common Lincoln Memorial, and most common of any US coin 1982 philadelphia, 10.7 billion. (Probably most common of any coin anywhere.)
Have no idea. One of these days I need to find someone who can do some reseach for me at the ANA library and find out. Back in 1982 Coin World published the coinage records from the mint each month, and they also published the news when they switched over from copper to zinc, It should be possible to use that information to get a fairly close estimate as to what the mintages of each type were. Just no one has ever done it and there are no actual mintage figures broken down by type.