The one, the only ACL (an Australian site dedicated to all thing Christmas Lighting with super-friendly members)
DoItYourselfChristmas (an American site dedicated to all things Christmas Lighting, again, with super friendly members)
My Lighting Sequencer of choice HLS (Hinkle's Lighting Sequencer)
Nutcracker v2 (online) software RGB effects builder - amazing stuff here people - check it out
Nutcracker/Xlights Nutcracker v3 - offline (pc install version)
Lightshow Pro (a lighting sequencer preferred by many enthusiasts)
Vixen (a freeware lighting sequencer)
Light-O-Rama (a lighting sequencer &/or hardware system for controlling lights)
Ray Wu A fantastic store located in China for all things lighting. Ray and his team are extremely helpful.