There's so much information on the internet regarding this topic, I am surprised you wrote as much as you did(!)
Yes, you will still often see black bars when viewing many different types of movies and tv shows on the typical HDTV. Yes, some laptops & monitors will require you to make some adjustments for optimal viewing of certain types of content.
We have pretty much covered the bases
Most TVs and monitors are 16:9 nowadays, which I've had some problems with, but I did some calculations and found something interesting and am wondering if I am correct. People complain about letterboxes on old-school monitors and laptops, but it seems if TVs and monitors displayed movies correctly, there would actually be pillerboxes (black bars on the sides) if it were scaled top-to-bottom, or letterboxes (black bars on the top and bottom) if it were scaled side-to-side.
Common Aspect Ratios:
Widescreen: 16:9, 16:10
Movies: 1.85:1 (typical) and 2.39:1
If I multiply the most common movie aspect ratio by 9 (since it is factored down to 1 vertically), the width actually becomes 16.65, or 4.0625% wider than typical widescreen TVs and monitors. This means you're missing over 4% of the image or it would have to have the boxes around it that everybody complains about. Am I correct in this calculation or did I miss something?
2.39:1 is also used in movies, but is less common. This would be missing 25.6% of the image without boxes.
1.85:1 x 9 = 16.65:9
2.39:1 x 9 = 21.51:9
Here's what they are translated to 16:10 (less common in monitors):
1.85:1 x 10 = 18.5:10
2.39:1 x 10 = 23.9:10
To have a 16:9 movie aspect ratio, it must be 1.7...:1.
To have a 16:10 move aspect ratio, it must be 1.6:1.
The Golden Ratio is 1.61803398875, or 16.18:10 or 14.56230589875:9, so movies and TVs and monitors are off if we're using that for our standard.
I realize that 4:3 monitors would have bigger black bars than widescreen, but considering the reason I heard for the move to widescreen was because letterboxes are annoying, they're still not eliminated in the typical movie (and probably TV show), so I don't really see that as a valid complaint. I do prefer 4:3 monitors for computing and laptops and work (which I rarely watch shows with), though I couldn't imagine anything less than 16:10 for TV (and 16:9 is fine), and letterboxes never bothered me. I just wish there was a choice for new 4:3 monitors and laptops.
Can someone correct me where I'm wrong or provide comments? Thanks.