This is the first batch. I'll try to get some more out tonight. I have to open at work tomorrow, so all the charts may not be posted until late tomorrow afternoon at the earliest.
Sorry for the tardiness. In addition to collating data and updating charts, I had to save local .png copies of a bunch of charts since the forum currently doesn't allow for direct copy-and-paste of images that are generated locally (such as in OpenOffice). This is a fairly time consuming process compared to the old way, so it may take me a bit longer to get some more charts out.
Anywho, it's clear that the PS4 & XBO are post-peak now. They both had their worst Q1 performances to date, with the PS4 being down 24.4% from last Q1, and the XBO being down a whopping 35%. For reference, the PS3 & 360 were down -24% and -27%, respectively, for 2012 as a whole, the year before they got replaced. The PS4's decline may be relatively normal for the first post-peak year, at least compared to this generation, but the XBO may be down considerably. Then again, the XBO had tremendous YoY improvements last year, with Q1 and Q2 in particular being up considerably thanks to the effects of the One X. First-half XBO sales last year were up 38%, with the gains being shared rather equally between Q1 & Q2, while Q3 was up only 18% and Q4 was down over 13%. So, it's still possible that the XBO's YoY drop will shrink as the year progresses.
Meanwhile, the Switch has experienced significant growth so far this year, with total Q1 sales growth of 20.7% year-over-year, despite no price cuts or new models. It also continues to vastly outperform the 3DS, and compared quite well to the PS4, selling almost 7% more units in Q1 this year than the PS4 did in Q1 2016. It was also the best Q1 performance of any Gen 8 console to date. With the arrival of Pokemon Sword & Shield and possibly a new hardware model later this year, the Switch stands a very good chance of selling over 7 million units this year if it continues this sort of sales growth. The last time any system sold over 7 million units in a single year was the Xbox 360 in 2011.
Right now, I think I'm confident enough to project year-end sales for each system:
The next batch of charts will focus on quarterly sales in general, and will include the requested Year 6 comparisons to previous generations.