Canada

You do realize that giving your vote away from a smaller party to a larger one leads us more into the two-party lockup that the U.S. faces right?

Always there's this one-sided thinking of "oh, but if you vote this way, then it's your fault when the party most opposed to you wins. Why do we never ask why the party that's most positioned to beat the party we're most in objection to isn't out there trying to appeal to us? Why must we appeal to them?

By deciding that your vote is a waste when it goes to a smaller party, then congrats! Your "strategic voting" dissolves support for the smaller parties which in turn leads to their eventual dissolution, and then voila, you end up like the states where the larger left-wing party ends up losing support amongst it's own base in pleas to appeal to Conservatives driving the overton window to the right.

EDIT: Quickly adding to this comment that if the Liberal candidate for my riding doesn't explicitly come out in support for proportional representation, I will be throwing my vote elsewhere. Sent an email, and keeping an eye on public events.