I would proberly say thigh just, slightly sweeter flavour. I prefer breast for some dishes though. People have a misconseption about breast being dry, if it is cooked well you can see the juice oozing out when you cut it.

Easiest way to cook a breast. Preheat oven to 200 C/ 390 F. Get a breast fillet with the skin on and bone still attached. Heat up a frying pan till its very hot, season chicken with salt and pepper both sides. Pour oil in hot pan and lay the breast skin side down in there. Cook for a minute or so until the skin is nice and golden, turn breast over and repeat. Put the pan straight in the oven if it is suitable or onto a tray. Cook for 10 mins or so until the chicken is just firm but still with a slight spring. Rest and serve.