Here are some images of my Dreamcast setup taken on my phone. I've had the DC connected to my main TV since I first had in back in 1999, but the DC and equipment has evolved over the years. I will show the controllers and peripherals separately.
Dreamcast
Translucent black case
TerraOnion MODE (500GB SSD + 16GB SD card)
DC-HDMI (PCM stereo / Full RGB colour / 960p in 1080p window)
Dream PSU
Noctua fan
Blue power LED
Audio
HDMI cable from Dreamcast to Denon AVC-X4700H amp.
I usually play audio either as stereo + sub or I use the amp to upmix to full Dolby Surround, either way it sounds great.
Video processing is basically switched off, I have it configured as a game input to minimise signal delay which is passed through to the TV.
Focal Chora 826-D Dolby Atmos front speakers
Focal Chora Center speaker
Mission 70DS surround speakers
SVS SB-1000 Pro subwoofer
TV Screen
HDMI cable from amp to 65" LG C2 4K OLED.
I play in game mode for the fastest response time, the TV scales the 1080p signal to 4K.
I sit about 10 feet from the screen so until recently I had to use extension cables to play using the original controllers. I now have a couple Retro Fighters Striker DC controllers with the longer cables and a DreamConn wireless controller.