Battlestar Galactica had the best VFX on TV, done by the best people in the VFX field. Here's some of my favourites from the show.
Opening shot from Saga of a Star World, Five battlestars with a majestic Stu Phillips music cue. The bar's raised straight away and it only gets better.
The attack on Caprica from Saga. Great combination of VFX and phyiscal FX to create an in your face scene of destruction.
Adama's medallion serves as the key to opening the inner tomb of the ninth Lord of Kobol. The effect looks like real word lasers. Anyway, it's the series' first nod to the mystical.
The shuttle crash from Gun On Ice Planet Zero. An effect achieved by what was then the old-fashioned way with the model flown on wires. So good, the same gag was repeated in the second season episode of Buck Rogers – Journey To Oasis.
Universal's Hartland FX unit more than matches the work done by Dykstra and co. in Fire In Space. The initial attack on the Galactica and the ship exploding are really spectacular, but the run on the landing bay to put the fire out by Apollo, Starbuck and Sheba is a nailbiter. The Freudian overtones of Vipers shooting white liquid into a cavernous opening I don't want to go into. Ron Moore will probably use the scene in GINO sooner or later though!
War of the Gods' lightship, beautiful and spectacular. 'Nuff said!
The reveal of Iblis's true face in War Of The Gods part two is very well done and a good use of tried and tested VFX techniques. Basically Macnee is double exposed with a performer dressed in a black costume and special make-up and a negative image is composited in to give a weird look to Iblis' costume. Add a red glow to the eyes and Bob's your uncle and Fanny's your aunt. Note that when Starbuck fires at Iblis, his gun issues a yellow beam effect when it should just flash. A nice touch is the beam pasing right through the Count and turning red and slowing down some!