Ok, well this remedy is going to sound utterly revolting... but I promise it's not quite as bad as it sounds.
Chop up some onion (not very much, < half a small onion), put into a cup or small bowl, and sprinkle sugar over it (any kind, though brown sugar makes it a bit nicer). Leave it for several hours, and it will form a syrup, which you drink.
I know that sounds totally disgusting, but the onion-y-ness is very weak, so it tastes mostly sugary. It works so well, because the onion has anti-bacterial and anti-viral properties. My mum was given it as a child when she had bronchitis and a whole host of other nasty respitory stuff.
And if you can't face that, as mentioned before, hot water with lemon and honey is great too. If your cough is because of gunk on your chest, avoid milk/chocolate and other dairy products, as they make your mucus thicker and therefore it's harder for it to do its job of lubricating your throat (mucus is a good thing! medicines that dry it up are not a great idea, if you can do without them)
Hope it gets better soon.