Not looking at silly prices, may be max £700.
After something special that isn't in a plastic case. Around 15" screen and above. And prefer compete coverage instead of "accents" that Dell use.
Some models I've seen so far:
Acer Timeline - price is bumped up for portability and battery life that isn't a requirement for me.
Asus U6V Bamboo - screen smaller than like, over budget, not sure if bamboo would contract with age and heat.
Sony VAIO FW series - looks best option so far. Magnesium case.