Best slim business orientated laptop?

[Bleek]

As per the title, what's the best slim business orientated laptop?

Requirements:

- thin/slim
- lightweight
- solid battery life
- plenty of processing power for multiple spreadsheets and office related tasks
- large high quality screen
- budget in the region of £500-750 but open to discussion
- Windows 7
- a warranty beyond a year is preferable

Thanks