Depends on the area, but Arborvitae (Thuja) and Junipers may be the choices. Check the biggest local nursery and see what they sell.

If in the shade mostly, neither will grow that fast or thick.

no opinion provided until you tell us where you are.. soil type.. and any other information that might help us ...

a picture would sure help ...

i like Thuja occidentalis 'Degroot's Spire' for thin ... and fast height.. it will do 12 to 16 inches per year .. once established.. and PROPERLY planted ... IF IT WILL PROSPER WHERE YOU ARE ...

it is preferable to go smaller.. and remove all multiple leaders, but one.. if snow load is an issue ... a single leader plant is snow proof

a pic of one of mine below

ken
{{gwi:242866}}

Here is a link that might be useful: link

We are in Colorado near Denver. The areas are sunny. I will try to get a picture up, soon.

Pretty Thuja.