I'd recommend Autoglym Fast Glass. It's popular so you can find it Amazon, Halfords etc. Importantly, it's also alcohol-based - which means it won't cause discolouration to the windscreen if it's tinted, and it shouldn't damage upholstery or leather. I'd recommend applying it with a microfibre cloth, too. Don't use domestic, household glass cleaners on your car - you can damage it because they're almost all ammonia-based.