The only set I've completed more than once was 1991 Maxx, the most common NASCAR set ever, but a favorite of mine. I ended up giving one of the sets away as a Secret Santa gift on a NASCAR forum. I don't remember where the third set went off to. It might be in my storage unit somewhere still.
I got them both when my local NASCAR store closed and gave me every card in the shop, which ended up being more than 2000 cards. Unfortunately about 90% of them were stored loose in buckets and damaged. The ones in binders were all duplicates, of course.
VERY slow trading due to health problems. Not transferrable so safe to trade with, just moving is painful and can't always access the cards.
Cardboard History My COMC
New Collection Website: Cardboard History Gallery (Still under construction)
Tips on how to make your scans look like the card does in hand (No more washed out, fuzzy scans!):