There is a colour system for grading gear, White being the lowest, Green, Blue, Purple, and then Gold, gold being the highest, so i suppose you could call it legendary gear if you like
If we look at the earlier games we have examples such as Mehrunes Razor, Scourge, Daedric Crecent and Umbra Sword. Some of them can be obtained in many games in the Elder Scrolls series. Might this not be what the original poster refers to?
I'm kinda interested to know if they make an appearance in ESO.
The wabbajack and fork of horripilation make a brief appearance in a quest, you get to use the wabbajack to boot. Other than that, nothing else really comes to mind.