I mostly watch the Japanese version. I watch German and English dubs occasionally for the lulz. I started watching Durara on English recently, and it's hilarious. Don't know if it's in the "so-bad-it's-good" category, but they always make me laugh when they talk.
The only shows where I really avoid dubs are shows like Yu-Gi-Oh!, Pokemon, Dragon Ball Z and similar shows. I used to watch them dubbed, but Yu-Gi-Oh! is a different show on Japanese. I mean it's obvious why (4Kids). Pokemon and Dragon Ball Z on the other hand have the same story, but they changed the script and edited some stuff.