I have been working on the Topps run (1951 - 1972, no interest in anything past that year), and am within about 53 cards of completion. However, I decided that the 1952 set ended at 310, and unless the girlfriend wins the lottery, I won't change my mind.
I also am working on the early Bowman run (1948 - 1955) and am within about 125 of that goal, 2/3 of those being 1949s, many still easy commons. I don't expect to ever completely finish this run, due to the early Robinson and Mantles, but it's fun and they are beautiful cards anyway, even in lower grades.
And I do collect the lower grades, because I am a collector, not an investor, or otherwise wealthy lad.
I have, for better or worse, become variation-addicted, and have found hundreds, perhaps thousands, of them by searching through boxes at shows and online. This pursuit will certainly continue until I am too old to fit a card in a pocket, as I am discovering new variations all the time. This makes card shows endlessly entertaining and fruitful, even now that my wantlists are becoming tough just as the wallet becomes thin. There are still many variations to be found that most dealers are unaware of, so "bargains" can be found by the diligent.
I have tried to assemble a kind of master list of variations (including errors and whatever) and the list can be seen at my webpage
https://sites.google.com/site/richarddingmancards/home
... just scroll to the bottom and click on the appropriate link.
Great thread, best of luck to all, and hopefully we can help each other accomplish our various goals!
Richard D
OBC, VCT, OCT, Dugout