Karting (or Go-Kart Racing) is the sport starting with K best watched on TV.
Hamilton, Verstappen, Leclerc, Norris, Russell, Alonso, Vettel, Räikkönen, Ocon, Gasly, Piastri — all started in karts. Watching karting = watching future F1 stars.
But for "need a TV to fully appreciate" — Karting wins. The speed, tactics, and future stars shine on screen.