Which PC/gadget has the highest pixel resolution?

Here I have collected and calculated PPI (Pixels per Inch) for some laptops and tablets.

Screen Diameter (inch)	Screen Ratio (Width/Height)	Angle (rad)	Screen width	Screen Height	Number Of Pixels (Horizontal)	Number Of Pixels (Vertical)	PPI
15.6	1.78	0.51	13.60	7.65	1280	720	94.14	HP Pavilion 2000T
15.6	1.78	0.51	13.60	7.65	1366	768	100.44
17.3	1.78	0.51	15.08	8.48	1600	900	106.11	HP Pavilion 17z Laptop
14	1.78	0.51	12.20	6.86	1366	768	111.92	HP Pavilion 14 Chromebook
15.6	1.78	0.51	13.60	7.65	1600	900	117.68
18.4	1.78	0.51	16.04	9.02	1920	1080	119.72	Alienware 18
15.6	1.60	0.56	13.23	8.27	1680	1050	127.00
17.3	1.78	0.51	15.08	8.48	1920	1080	127.34	HP ENVY 17t 1080p
15.6	1.78	0.51	13.60	7.65	1920	1080	141.21	HP ENVY 15t Quad 1080p
15.6	1.78	0.51	13.60	7.65	1920	1080	141.21	Dell XPS 15
8.9	1.60	0.56	7.55	4.72	1280	800	169.60	Amazon Kindle HD
17.3	1.78	0.51	15.08	8.48	2560	1440	169.78
15.4	1.60	0.56	13.06	8.16	2880	1800	220.53	Apple Macbook 15.4 with Retina Display
13.3	1.78	0.51	11.59	6.52	2560	1440	220.84	Toshiba KIRAbook™ 13 Ultrabook
13.3	1.60	0.56	11.28	7.05	2560	1600	226.98	Apple Macbook 15.4 with Retina Display
14	1.78	0.51	12.20	6.86	3200	1800	262.25	HP TouchSmart 14 Ultrabook
8.9	1.33	0.64	7.12	5.34	2048	1536	287.64	iPad 8.9" with Retina Display
7	1.60	0.56	5.94	3.71	1920	1200	323.45	Amazon Kindle HDX 7"
8.9	1.78	0.51	7.76	4.36	2560	1440	330.02	Amazon Kindle HDX 8.9"

So far, nothing can beat Amazon Kindle HDX, not HP not even Apple iPad with Retina display.  Because the price of a laptop is significantly higher with higher PPI, the affordable price of Kindle plus its highest PPI makes it the best gadget for eyes and pocket!