Wow! I’m lost for words.
I started collecting Pikachu Cards about four months ago and currently have around 250 (with 50+ incoming), but before I saw your list I didn’t even knew which were all in existence, and how much there were in total. I know I won’t be able to have a collection like yours, for two reasons: 1. I’m as of yet not paying more than 25 USD for a single card (and the ones I did pay 15-25 USD for had to be very special / cool to me personally). And 2. It isn’t my main collection - this is (twisty puzzles).
Also, thanks for sharing that Excel. I was currently in the proces of making a checklist in Excel myself, but you saved me a lot of time. Hopefully I can ever help adding new card to the excel list that I find before you. 
I tried to find a single Pikachu in my collection you didn’t had yet, which of course was futile… xD I did see two Ditto Pikachu cards you were missing though, although I’m sure you’re aware of it or haven’t updated your site yet (English XY40 & Japanese 077/XY-P).
Keep up the great collection!
Greetz,
Kevin