Location, location, location
I made the switch a few years ago.
You get many vague suggestions because, as a couple of the posts stated or hinted, your requirements for over-the-air digital broadcasts are very location-specific.
You can use the same TV unit to bring in two primary program sources:
1. Over-the-air digital broadcasts
Requires antenna to receive the broadcasts and send the signals through coaxial cable into the TV tuner. I just took the satellite dish off, replaced it with TV antenna and plugged the antenna into the same coaxial cable that eventually leads into the TV.
Image quality actually of high resolution 1080 broadcasts improved over the satellite provider. Explanation was that signals that the satellite provider compressed to conserve expensive bandwidth (supposedly the same with cable) are no longer compressed with over-the-air broadcasts.
After testing that a directional antenna works at my location, I took the satellite dish off, cancelled service, clamped the antenna onto the same post that the dish was on.
2. Internet streaming through various web sites
This still requires you to pay for internet service, and additional fees for streaming services/sources such as Netflix, Amazon, etc. The signal goes through a CAT5 or CAT6 cable, same as your computer internet source, and the cable plugs into a separate (from coaxial) port in the back of the TV. Many TVs capable of Wifi so no ethernet cable needed, but I think the signal and bandwidth are better with direct physical connection.
Start with the Federal Communications Commision's Digital TV Recption Maps site that bigwheelzip stated above. Enter your address and it will show the various channels, signal strengths that you are expected to receive, based on your location. Read the "Please note" section as it describes the variables that can affect your reception. There's another site antennaweb but it's not as accurate; states I should get 0 stations when I actually get almost 40.
By clicking on each stations callsign, you'll get more detailed information such as "Compass Direction to [broadcast] Tower" which will be relevant if you use a directional antenna to have more signal gain if you're at the fringe of the "Gain/Loss Map" which shows the approximate range of the station's broadcast signal. Theoretically, range is line of sight, but clutter, terrain, interference limits the near ground level signals.
At this point, you can decide which stations are more important to you, and whether you're close enough to use an omnidirectional antenna to receive most or all stations, or if you have to use a directional one. Directional means you may have to omit some stations, or go with an antenna rotator which adds complexity.
Using indoor antenna degrades signal significantly, unless you're near the broadcast towers. Again, highly location-specific.
Your best bet is to look the the FCC site information that pertains to your location, buy an appropriate (highly directional, omnidirectional, indoor) antenna, and test the reception quality. Make sure your antenna purchase is returnable or exchangeable.
I'm lucky if I see YouTube videos all the way through without the spinning orb and a frozen viewer. Or it'll be so jerky you might as well turn the sound off. I can't imagine trying to watch that mess on my TV. 
