I have always found African wildlife photography totally addictive. That sense of anticipation you get when you are heading out before dawn, knowing there could be a good chance of photographing something truly spectacular on any given day.
However, I get the same sense of excitement heading out in the mountains in the UK, especially on those days when the light is changing every few minutes and you feel a perfect photograph is right at your fingertips, if only everything would just come together. So rather than having one favorite place, I like the variety that keeps the sense of excitement and exploration alive.