The anaglyphs of "It Came from Outer Space" and "Revenge of the Creature" were perfectly watchable on the big screen (at least, they were in 1981). Who knows what condition they're in now.
They were the only option just before the 80s 3D stampede.
Sometime later I also saw a very impressive...
The absolute worst anaglyph system is ColorCode which uses purple and amber lenses plus a lot of wishful thinking. It seems designed to put people off 3D.
Channel 4 in the UK showed "Friday the 13th 3 3D" and "Flesh for Frankenstein" in ColorCode several years ago and they were barely watchable...