This one's a toughie. But in the end I went with the 2007 Red Back parallel. Does anyone even remember those? So 2007 was one of those years I was working a lot. And at the time that meant I was working out in the field doing biology stuff. So I didn't really open much product. Fast forward a year or two and I decided I want to put together the base set, so I order a couple boxes of Series 1 and Series 2. I can't remember if I went with hobby boxes or retail jumbo boxes or exactly which format I bought, but I do remember that I had a ton of the Red Back parallel cards from both series. So many in fact that I had the crazy idea of trying to actually put a base set together of the parallel. And you know what, I'm pretty close. Unfortunately with the birth of my son and the lose of my man cave I had to put that project, like all my other small projects, on hold.
So here's the crazy thing, the Red Back parallels the only difference from the base set is the lettering on the back is red and not white. Here's another interesting fact, this was the set that started the photo variations and gimmicks with Derek Jeter's card featuring President Bush and Mickey Mantel photoshopped into the card. Here's another interesting fact: The card that features Bush and Mantel, which wasn't short printed in anyway is much more expensive than the corrected card that was put into the factory sets and produced in much fewer numbers that doesn't feature Bush or Mantel. Ahem.
Anyways, the Jeter red back is still one of the cards I need to complete my Red Backs set and a few years ago it was still way too expensive for my tastes. But here it is in all it's glory.