Earlier this summer I received my all-time farthest analog or digital TV logging when WTCE (licensed to Fort Pierce; transmitter even farther south toward Jupiter) came in at the vacation home I was staying in just outside Charleston, SC. 391 miles according to Google Earth. It came in long enough to decode PSIP and briefly get a viewable picture. I was only using a Mohu Leaf indoor UHF antenna with a Hauppauge USB stick on a laptop. I also got several Orlando and Jacksonville signals there, as well as nearer Columbia, Florence, Savannah and Wilmington stations.
The farthest away I've logged TV at my current home (about 20 mi NW of downtown St. Louis) is KSMO Kansas City at about 225 miles, with runner-up KYTV Springfield/Fordland (about 176 miles). I live in a northwest-facing valley so even local reception is 1edge and impossible without a rooftop or outdoor antenna; I have an Antennas Direct UHF/VHF antenna on a 14-foot mast up the hill in the back yard for a total height of about 20-22 feet above the house. With this setup I get full-power Hannibal/Quincy FM throughout the day and usually get KHQA and WGEM TV in the early morning hours.
During the analog era I was in Nebraska 23 mi. SW of downtown Omaha and my most distant identifiable log was KWKB Iowa City when it was a WB station, at about 250 miles. I'd see shadowy black and white signals on channel 2 in particular but was never able to accurately pick any out.