I would say that the most difficult kind of PS to write is one that applies to two opposite courses; I applied to four Criminology courses and one Performing Arts course, so had to make my PS relevant to both - absolute nightmare.
I'm going to go with Abuse Studies/Dance. Which yes, IS a real course (at man met). And the good news is that it's still accepting applications!!
Creative arts - like fine art, drama, dance, photography, even music to some extent. What's the quote? "writing about music is like dancing about architecture"
MORSE. its unique so you would have to write a personal statement on it and other different courses.
I did a degree in Maths and Physics. Can you imagine trying to write a statement which somehow gets across the blatant lie that Maths and Physics are remotely interesting subjects? awful...
How can you express passion for teeth over everything else in the human body?!?!?
I assumed Dentistry would be quite difficult, but when helping a few friends with their personal statements, it actually wasn't that bad. The introductions and endings are always difficult however.
I would say Economics simply because that's what I want to do and have no clue what to say. :/
Probbably something like Medicine, Dentistry, Optometry, Vetinary Science or any course at Oxbridge (and maybe at Russel Gropus unis).