@ReeRi
Yes exactly but I said to start with I know they can park where they like just not sure why here!
As I say, YANBU. 
Every car in our cul-de-sac (of 26 houses,) has a 2, 3 or 4 car drive. Yet almost every day, visitors park on the road. The woman who lives opposite us has a 4 car drive, and she often has 2 or 3 cars visiting her (at the same time,) and they NEVER park on her drive; always opposite ours, making it hard for us to get out (or IN, if we have been out.)
Sometimes we just think 'if you can't beat 'em join 'em' and park on the road ourselves, at the foot of our drive, for 4 or 5 days in a row.
Cue a load of tuts and huffing, and staring at our car, and comments like 'why is their Astra parked on the road?'
as they have to park 60 or 70 feet further away, because they can't park on the road, (next to her drive,) because they'd be blocking the road.
They also find it hard to get on the drive with us parked at the foot of ours. Doesn't matter though, because if we WEREN'T there, they STILL wouldn't park on the drive anyway.
So basically, they park on the road, often opposite our driveway, making it very hard (sometimes impossible) for us to get out - or in, but when WE do the same, they stand there bitching.
I think the people on here who think parking on the road, opposite peoples drives is OK because it's a public road are the ones who do it themselves. But you can bet they'd kick off if someone kept doing it to them. 
Luckily, our house is elevated, and around 7 feet higher than the road, and our front garden is 40 foot long, so we don't have people gawping in the window, but it's still annoying.