Ekko's W + Zhonyas
Something I found hilarious while playing Ekko was that if you are in your W (Chronosphere) and you're in statis from Zhonya's, the stun will go off still.
Probably the most fun/reliable way to procing your stun, at the expense of losing your shield and a good chuck of your "free" damage on your stunned quarry.
Makes me wonder if you can pull of similar effects with GA - would be useless to you since GA statis is 4 seconds, but a nice little act of martyrdom for your teammates