Freeze dried coffee that tastes good. No, it's not as good as brewed in the states. It's not as good as french press coffee, but it is quick. It is always hot. And it tastes like coffee. Nescafe is the only kind I feel is just gross, and it is the only kind I've ever drunk in the states as well.
As an FYI, do not drink brewed coffee in restaurants in England. It's called filter coffee here, and it has generally been left on the burner all day. So you end up with burned coffee that has been poorly measured. Sometimes it is two days old. Yuck. If you're desperate ask for an Americano with extra water.