Tarragon: French vs Russian vs Mexican
It is all a question of taste, so there is no definitive answer.

As a purist, you should plant "French Tarragon" which is the proper Artemisia dracunculus plant.

It is not an intense flavor; and this is why it is so good (IMO) and will not overpower a dish.

If you want something stronger, grow the "Mexican tarragon" (Tagetes lucida), which is a different plant.

Both have their use; plant both.