Damn, that's a close call. IIRC Electric Ladyland was the first album to incorporate some really new & powerful amps etc., resulting in the unique sound only he ever had.
I've read some sound engineers from the company that was making his stuff (forgot the name of the company

) went back and tried to reproduce the equipment.
They failed. They concluded Jimmie did some "after market" voodoo to the stuff and they couldn't figure out what the heck it was and gave up.
EDIT: I'd have to say my favorite song is "Red House". But there's more than 1 version. To me one is clearly superior. But I don't know to differentiate between them. Like recording date or something
Fern