Except for being slightly lean in the bass, Grado SR60 series is the one to beat. They are an open-back design, so might distrub others under quiet conditions. That said, I haven't heard them, but the Sennheiser Momentum on-ear phones seem to be right up your alley. Read a review here.
I have been impressed by the sound and value of the Sennheiser HD 419 / HD 429 / HD 439 / HD 449 series. The HD 449 started out at close to $200 retail, then the price has dropped and dropped and is now down to $120 retail and only $49 at Amazon. They sound great, are super comfortable, closed design is good for privacy. For under $100 I would start with the HD 449, it probably beats most other 'phones under $100 by any other manufacturer.
They definitely meet your "rich, full bodied" criteria. Bass is strong but not bloated like some 'phones.
Thanks for all the feedback guys. I'll look into these. I currently have some cheap Sonys that sound alright for when I'm working in the office but I'm hoping to find some for my "zone out" sessions at the end of a long working day. Thanks again!