Reading - mostly fantasy and sci-fi, as well as medical texts (for a second degree as well as for fun), although my fillyfriend has persuaded me to plough through all the classics in my library. I estimate I'll be finished by 2076, if I'm lucky.
Writing - really, this goes hand-in-hand with reading, and I've always loved making up my own stories, characters and worlds to bend to my whims! Mwahahahahaha...ha...ha...ahem.
Riding - I live deep in the country, and for my family, riding is practically an obligation, as it is for most of m'friends, as well as being jolly good fun! We have a few excellent horses in stable right now, including my personal favourite, a champagne cremello called Mystic who I can never get enough of.
Hunting - goes hand in hand with the riding, in my neck of the woods. Not so fond of riding to hounds for foxhunting, but I do love a good chase, or a deer-stalking, or pheasant-shooting, since I can (and do) eat the fruit of my labours.