i know two so far.

RIng of Viper eye
and Ring of Dessication :celebration:
if you know any more please post them im not sure if its just for PS3

I know the Ring of Vipereye has perm quest item glitch, meaning it's always 0 weight, but you can't drop it. I didn't know that the effect is perm??

truth is all i had to do was keep wearing the ring eventualy ring of dessicration stuck on effect but i could wear two other rings...

It ordinarily isn't, but some items can have their effects permanently bestowed on your character by a http://www.uesp.net/wiki/Oblivion:Glitches#Permanent_Effects_from_Quest_Items.

this can also be done with the boots of springheel jack, +50 acrobatics and no fruity shoes have to be worn anymore :celebration:

i like the ring of dessication perma water walking and breathing