Costa Coffee

You're rushing between the British Library and your next appointment, or you've got twenty minutes before your train pulls out—this Costa is exactly where you'd duck in. It's tucked into the Kings Cross & St Pancra station complex on Euston Road, so it's busy, it's functional, and it does what it says on the tin. The coffee is competent rather than exceptional (it's Costa, after all), but they're consistent with their flat whites and cappuccinos, and the pastry selection keeps you from feeling like you're just refuelling. Given its location, it's naturally heaving during rush hours, but if you time it right, you can actually claim a seat and enjoy your brew without feeling like you're in a commuter scrum.