I don't think there's been anyone quite like Jeff Buckley. I prefer his father, especially his earlier stuff and then things like Lorca and Starsailor. I don't feel much similarity between Jeff and Nick Drake. If you want to go more towards the maudlin/drama side (but still good), you might find Rufus Wainwright interestingly close to that part of Jeff. Then in a more dispersed kind of way, I do have an association somewhere between Jeff and Nick Cave. But then it gets weird because I associate Nick Cave with Jim Morrison and Richard Thompson.
Anyway, all of those people are worth listening to, all uncompromising in their own ways.
- Ed