I'd specify two main reasons why I like Planethoster:
1. Tech Support – Whenever we have had technical problems we found their tech people very fast to respond, courteous, knowledgeable and helpful. Having dealt with many tech companies in the past, I know this is rare and valuable.
2. The Interface – I love their interface. It's clean, intuitive and easy to navigate with lots of great features that make managing a web-site a snap. Keep up the good work!