I get signals from 30 miles away, line of sight, with a Terk HDTVa (amplified). They are mostly duplicates of the stuff from the main towers in the opposite direction, so I don't pay much attention to them. But they can be tuned, and occasionally even come in off the back end of my antenna in the garage attic. The best spot for me turned out to be the middle of the room, not the window. Eventually I moved it to the garage attic, to cut out interference from people, microwaves and airplanes.
The Terk is a combo antenna, UHF resembling the silver sensor, plus rabbit ears. Some people have used outdoor antennas indoors, they just put it on the wall or in a weighted stand. My other antennas are homemade 4 bays. They do as well as the Terk except in my worst room, away from the towers. For that the amp helped me get the last two stations. When I got my Terk, Amazon was the best price, but it varies. There is something to be said for buying local, so you can try a few out, and return the ones that don't work.