Insignia is Best Buy's house brand. They own Insignia. They're not generally top-tier products, but they're more deluxe than Best Buy's other house brand, Dynex. Best Buy also produces its own accessories (cables, mounts, audio, etc.)
The new Insignia Connected TV is the first smart TV from the retail giant's house brand, and it's also the first connected TV that runs the TiVo interface.