Righto.
I'm not looking at a 'league table' of 'terrible empires'.
Look at each of the continents where Britain had territories, and most of the native empires in their heyday were worse. Maybe you may feel a liberal's shame at being the sons of empire. But people from these colonies who've learned about their native histories would be able to regale you with the glorydays of their own empires, and they'd got up to. You reckon it's trendy to talk about Iraq and a war for oil? There's little evidence that war was fought for oil. Compare, instead, with the War of the Heavenly Horses, celebrated by China, where the Chinese empire subjugated a foreign territory for the sole purpose of gaining access to war horses. The Chinese lost most of their expeditionary force in the process, but it was deemed a victory worth celebrating, as China received a regular tribute in prized horses, and people were worth less than horses. The loss of 20,000 soldiers was a price well worth paying for securing an annual tribute of 1,500 horses.
If people want to talk about Britain's terrible history, maybe they should broaden their horizons a bit and learn at least a tad about the history of other parts of the world too. Howard Phillips said the British treated the Maori like shit, linking to the wiki article about the New Zealand wars, which didn't support his assertion. As a comparison with that article, try reading about the creator of the Ka Mate. He was in dispute with Britain towards the end of his life, but the British decided not to pursue matters as he was elderly. In contrast, in earlier years he engaged in pretty vicious inter-tribal wars.