I was going to suggest Pyracantha - aka Firethorn - but someone else did.
The plant does very well against walls, is quick growing and will be covered
with white blossom in the spring and orange or red berries at this time of
year.

Pyracantha atalantioides is a vigorous upright/arching evergreen shrub which
will grow higher than your garage roof. It will be covered with red berries
at this time of year. P. coccinea evergreen and bushy will grow to 12 feet
(height and spread) it has bright red berries. P. Orange glow upright dense
evergreen to H 15ft, S 10ft orange berries.

I suggest a combination of red and orange berried plants. They have good
spread and could be planted fairly close together to give an impenetrable
barrier.

Geoff