System Information - Things like CPU Temps, Clock Speeds etc.
Press Home x5 > Fast Forward> Down > Rewind > Down > Fast Forward
Wireless Settings - Things like signal strength, drops/retries etc. Can be used to adjust your 2.4 gHz strength to just the right level (anything better than -70 dbm seems optimal)
Press Home x5 > Up > Down > Up > Down > Up
Limit streaming bandwidth - Handy if you have datacaps and want to manage a heavy streamer etc
Press Home x5 > Rewind x3 > Fast Forward x2
Random Secret Screens - Disable scrolling ads etc.
Press Home x5 > Fast Forward x3 > Rewind x2
Press Home x5 > Up > Right > Down > Left > Up
Developer Options - Webserver to take screenshots of rokus etc.
Press Home x3 > Up x2 > Right > Left > Right > Left > Right
Force Restart - When you are too lazy to walk up and power cycle it.
Press Home x5 > Up > Rewind x2 > Fast Forward x2.