Which voting systems do not have tactical voting? Specifically, expressing your true preference on a ballot will not result in a less favorably outcome.
I'm looking at both multiple-winner and single-winner.
One that I know off already is random ballot, and dictatorial.
By Gibbard–Satterthwaite theorem, any resolute voting rule that satisfies Pareto and which is non-manipulable (i.e. doesn't have tactical voting) is necessarily a dictatorship. See theorem 3.1.2 in Social Choice and the Mathematics of Manipulation by Alan D. Taylor.