What flatscreens (if any?) have automatic ratio adjustment depending on the input signal?

so... none then?

Ratio adjustment? I think usually the player does the job. And it's only between 16:9 and 4:3 (anamorphic/non anamorphic). I don't know any player that can tell whether a movie is 2.35:1 or 1.85:1 or whatever other aspect ratio any film might be.

I'm not talking about the player. I'm talking about broadcast television.

For example... on my parents flatscreen tv, you can select a view mode, either 16:9, zoom1, zoom2, and 4:3. When a television show comes broadcast in letterbox ala ER, fine... 16:9, looks great, no problems... when a show that is broadcast in 4:3 comes in, everybody looks squished and flattened out... so you have to manually either select zoom1 which sort of tries and compensate, zoom2 which REALLy cuts everything off, but fixes the "squished" factor, or manually select 4:3 mode, which then adjusts the image to the old square style, and basically puts the black bars on the right and left side of the picture... it doesn't read the signal, and adjust the setting automatically..

...am I making sense here? Are their models that will just automatically adjust the viewing mode based on the signal it is sent??

The TV is really dependent on the signal. As mentioned, anamorphic is well known and they adjust for that appropriately in most 16:9 modes. But it really depends on what you are sending the TV. TVs with a tuner might have more options due to the tuner, but that won't help you for HBO.

It also depends on the wire. TVs will offer more zoom options on analog inputs than HDMI. And then it can depend on HD vs SD signal, too. (resolution)

I try to use my source to zoom/squish if at all possible. My HDTivo has 2 modes, for instance. And I use HDMI to connect. Neither mode affects HD sources. For SD sources, one stretches and one doesn't. So I generally leave it in the mode that doesn't stretch since I want the 4:3 in OAR and it doesn't matter to HD. This allows the TV to just stay in 16:9 mode.

I'm sure some TVs are slightly better than others and you could try to research that with specific models, but overall it is more a source/wiring/resolution issue since the TVs can only do so much.

I just assumed all TV did what you're describing. My TV (Olevia 337H) has a mode called "Aspect" which displays the programming in its native ratio. If I swicth from HD to SD, it will go from 16:9 to pillar boxed 4:3.