“I don't do anything in a vindictive manner. Look at my 14-year track record in Gujarat. People don't vote me to power to take revenge.”

Slim Burna on his Twitter http://twitter.com/slimburna1/status/377151400725467136, @Slimburna1 (September 9th, 2013)

Springfield, Ohio campaign event http://www.whitehouse.gov/the-press-office/2012/11/02/remarks-president-springfield-oh,
quoted in * 2012-11-02
Obama to supporters: Voting 'best revenge' against Mitt Romney
Joe
Newby
Examiner
http://www.examiner.com/node/54880521
2012-11-03 and * 2012-11-03
Obama tells crowd 'voting is the best revenge'; Romney freaks out
Laura
Clawson
Daily Kos
http://www.dailykos.com/story/2012/11/03/1154805/-Obama-tells-crowd-voting-is-the-best-revenge-Romney-freaks-out
2012-11-03
2012

Source: Point Blank

Snopes.com found no record of Sanders saying those words. https://www.snopes.com/fact-check/bernie-sanders-told-supporters-hed-never-tell-them-how-to-vote/ May be derived from a statement during an MSNBC town hall in April 2016:

We are not a movement where I can snap my fingers and say to you or to anybody else what you should do, because you won't listen to me. You shouldn't. You'll make these decisions yourself.
Misattributed

http://www.youtube.com/watch?v=U5gw1yEV0gs

Variant: I hated high school. I don’t trust anybody who looks back on the years from 14 to 18 with any enjoyment. If you liked being a teenager, there’s something wrong with you.

Interview with Oprah Winfrey (2004), reported in Luke Henriques Gomes, " George Michael: from tortured star to pop icon http://thenewdaily.com.au/entertainment/music/2016/12/26/george-michael-bathroom-incident/", The New Daily (December 26, 2016).

http://www.upi.com/NewsTrack/Sports/2004/12/22/mike_tyson_my_life_sucks/8085/
On himself

"Exclusive Amit Shah Interview: People are waiting to vote for Modi," 2013