Second Try (before seeing the change that Foitn made to his riddle)
Is it:
A car
I can be found all around the globe,
Everywhere can be found cars. Even on the north and south pole although these look very dfferent then your normal car.
Everyone has seen me, I hope.
Everyone must hope to see cars when crossing a road.
I come in lots of colors and shapes,
Cars can be found in many different colors and shapes
I don't make it better, the landscape.
Cars, roads and engine gasses are not too nice for the landscape.
If you don't see me you'll pay
Car accident
And you regret that all day.
You will probably have to visit a hospital (or worse), because of the accident
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Original post (where Foitn said it was the wrong answer)
Is it:
A street light?
I can be found all around the globe,
Every country has street lights
Everyone has seen me, I hope.
Everyone that isn't blind can see them. See second to last line for if you didn't see it.
I come in lots of colors and shapes,
They can have different color's and shapes, as long as they give light.
I don't make it better, the landscape.
Sometimes they just don't fit the landscape they are placed in
If you don't see me you'll pay
Knocking with your head against the street light post
And you regret that all day.
You will have a headache the rest of the day