Well I have my ideal controller in mind, and I've been running under the assumption that it's out there: I just need to find it.
Basically what want is to control hardware by midi, I don't really need computer/software interfacing because I just can't be creative with a computer as my interface. Basically I want something with a powerful built in arpeggiator, and a powerful built in sequencer. For the sequencer I'd want something where I can save an X-bar sequence to a button, and another Y-bars of sequence to another button, and then press buttons 1-through-z in order to create a whole song structure that will play consecutively (like Y x 3, X, Z x 4, Y, etc.).
To me, this seems like a basic want from a controller, but my initial forays into searching the controller world suggest this isn't a thing.