Question

This jacket does not suit you. You.......... buy another. (Fill in the blank with would /should)

Answer 1

this jacket does not suit you . you should buy another .

here the sentence is giving the sense of giving suggestions , and "should" is appropriate and is used when giving suggestions or advices whereas "would" is generally used to show compulsion

hope this helps

Answer 2

This jacket does not suit you. You should buy another

Here Would isnt probable as it expresses a probable condition .
So to make a suggestion and expressong the true thing that jacket doesnt suit .We are using Should .

Hence ,The answer is “Should ”