For business - The Giulio Cesare, Rome. Finding a good business hotel is like selecting an airline - functionality and convenience are prime considerations.
And I like places with a gym or a pool, because I reckon I've spent 50% of my time on planes over the past couple of years and it gets brutal if you don't work out. The Giulio Cesare is great - it's close to Rome's business district, and it has good internet connections in every room. It is popular with international travellers, so you can read newspapers from any part of the world over breakfast. The staff have a sense of urgency, which is unusual in Rome, and they can get you a taxi anywhere within three minutes. It's not that spacious, but it is comfortable and relaxed.
For pleasure - The Westcliffe, Johannesburg. Although I travel so much for work, I'm always on the lookout for new places to visit on holiday too. I pick up tips from friends and colleagues and read the travel magazines.
I look for personality, atmosphere and interesting surroundings. The Westcliffe is one of the most amazing places I've ever stayed. Converted from a town house complex in the old part of Johannesburg, it's elegant, spacious and looks fantastic - the outside is painted a glorious deep shade of terracotta. Inside it is luxury personified, very discreet and the staff are wonderful yet almost invisible. I stayed for five days the first time and it was so quiet I thought the hotel was empty; I later discovered it was nearly full. That's great service.