My horse HATES being groomed in the winter, especially winter into spring when he first starts molting. He gets itchy and it is all very traumatic! However, yesterday was lovely as it was a warm day (well warm in this current climate at least!) and he had been bitten by flies/ midges and really loved me curry combing him. It just depends what mood he is in XD
Places he hates most are in-between his front legs and face! Then he gets really ticklish when I do the inside of his back legs but he likes that if you're gentle.
Another problem is, I don't particularly like grooming him in winter/ when he's muddy as I am allergic to dust so it is just something we have to suffer with together!