This article, "The 20 Most WTF Magical Items in Dungeons & Dragons," is a fun read.
For some inexplicable reason, I found this one especially hilarious:
13) Druid's YokeIf you're in a D&D campaign where you need to do any kind of farming, you have bigger problems than any magical item can fix. But this yoke allows characters to — when they put it on themselves — turn into an ox. Not a magical ox; a regular ox. Then you can till your field yourself! You can't do it any faster, because again, you're just a goddamned ox, but it does allow you to… do the horrible manual labor… instead of the animal you've bred for this exact purpose. So that's… something someone would totally want. The best part? Once you've put it on, you can't take the yoke off; someone else has to do it for you. Because you're a goddamned ox.