Equipment rack:
This is a 4-post telecom-style rack I got used from a place I used to work at for $50. It's secured to the concrete under the stairs.
It contains my A/V and networking gear for my basement. The "den" area has the home theater. The kitchen has a 32" TV and Logitech speaker system for watching TV/surfing the web/etc while cooking. The bedroom has a 32" TV ceiling-mounted over the foot of the bed. All cabling is run through the walls with no visible wires anywhere.
Most of what I use my system for is listening to music, very little of which was recorded in surround sound, so I'm running simple 2-channel stereo everywhere for now.
From top to bottom:
Top shelf: 3x Intel NUC PCs (Intel i5 CPU / 16GB RAM / 240GB SSD), one connected to each room with a TV downstairs - the living area, kitchen, and bedroom. Each computer is connected to the TV in it's corresponding room via a 50-75' HDMI cable and a powered USB 3.0 extension for the keyboard/mouse receiver.
Carver TFM-6CB amplifier for running the KRK Rokit studio monitors (tweeters/midrange speakers for home theater room).
Seismic Audio LE-3000 amplifier for running the SA15 main speakers.
Behringer 9-channel equalizer (and, not quite visible to the left of it, an optical to RCA digital-to-analog converter).
NetGear gigabit Ethernet switch (unmanaged)
2x APC IP-connected Power Distribution Unit These are awesome. It lets you control power outlets individually via a web interface or Telnet. I have a script on the desktop of the living room PC that allows you to: Press 1 to turn off all amplifiers and A/V gear Press 2 to turn on all amplifiers and A/V gear Press 3 to turn on KRK monitors only Press 4 to turn on SA15 speakers only etc...
Each component can be power cycled, turned on or off, etc. from any PC or my Android phone.
Bottom shelf, from left to right: CyberPower 1500VA UPS Another Intel NUC running Server 2012 Standard acting as a domain controller for the local network and hosting a virtual machine for torrenting. NAS unit with 4x 4TB drives in RAID5 (10.8TB usable space) for storing music and movies.
In another rack upstairs is my modem, firewall, WiFi AP, a cable box and Slingbox (for streaming cable TV to any PC/room) and another UPS.
"Den" / Home Theater Room:
Yes, I know I need baseboard molding.
JVC 65" 1080p TV
2x KRK Rokit studio monitors
2x Seismic Audio SA15 speakers