Which transitional word is best used to indicate difference

the best one in my opinion is on the contrary but here are some examples

ExpressionFunction

On the contraryOpposition (not x but y). Follows a negative statement and elaborates

On the other hand          Comparison of two choices or two sides of an issue

Nevertheless, Nonetheless                Shows contrast between expectation            

when completing a research project

explanation:

irony  

i hope this you and have a good day

~ashbelle