I always buy this first when building a home theater, and it's not what you'd expect

When building a home theater, starting with an AV receiver is recommended before choosing a TV or projector. A good receiver centralizes audio and video, supports room correction, and allows incremental expansion of speaker setups. Key specs to check include HDMI pass-through resolution (at least 4K), number of audio channels, and connectivity options. For display, projectors offer the most immersive experience but OLED and Mini-LED TVs are valid alternatives. For content playback, an HTPC gives access to the highest surround-sound codecs, though streaming services may limit resolution; Apple TV 4K is noted as the most reliable streaming device.