TL;DR -- Vizio D24-D1 (2015 Model) works decent with RF on Atari 8-bits. It has composite, but no S-video...
A downside is "normal" unstretched video doesn't fit the screen, so black borders all-around. The "zoom" option loses part of the main display (not just the overscan, but also at least 1 row of gr 0. text). Sound is above average (for a LCD)
So I have an Atari 600XL and Atari 400... neither have composite or svideo-out*. Inconvenient because I have LCD monitors which support that. This leaves my Atari in the guest room, where it has a nice old 35" CRT TV. Problem there is it's so far from my window-facing work desktop, and all my electronics and Arduino stuff.
*(I'm holding off on one of the traditional video mods, as someone is working on a really nice new video mod. I forget the thread from Nov. but I'm sure folks know what I'm talking about)
The point.. oh yeah. I was willing to get a new secondary monitor, or TV. I'd read that lots of new TVs are not able to tune NTSC analog, which would mean the Atari RF modulator wouldn't work. You want to look for a TV (in addition to ATSC) with "NTSC" or "analog tuner pass through".
Some TVs are phasing analog out. The good news is that there is a HUGE market for "portable TVs" with analog reception, because that is what a lot of hotels/motels use to broadcast content (this was all pre-Internet, but this short range over the air delivery method is still in use). You can assume a portable will support NTSC, but the larger sets, well, that's a bit of Google to figure out. (You can't search Amazon and filter by sets having NTSC/analog support).
Atari since 1983 (1200XL, later ST). Now a Linux freak who uses a Mac at work.