I actually just wrote about this topic about a week ago in the Blog Bat Around, when I wrote about the hardest set to complete. It's actually the very same set, the first card set I ever got, 1988 Leesley Bigfoot, that I have been working on since 1988! Still 9 cards short.
This is going to be a really short post because I just wrote about it on my own before this 30 Day Challenge began. But the least I can do is show a different card from the set than I showed then.