Togekiss

The move rebalance on July 9, 2019 gave Togekiss the much needed addition of Charm to its movepool, which allows it to finally have a double Fairy moveset. While this doesn't let Togekiss reach the DPS numbers that Dragon-types can, the benefit of having a double resistance (in PoGo there's no immunity) to Dragon-type attacks lets Togekiss become a very tanky option if needed. 

On defense, Togekiss is acceptably bulky, shuts down Machamp, and resists Dragon. It has just Metagross whom it really fears.

Best PvE Offensive Moveset

• Charm + Dazzling Gleam lets Togekiss do what it does best: Fairy type offense.

• Aura Sphere actually offers more DPS than STAB Dazzling Gleam. However, its use is limited to targets that take super effectively from both Fairy and Fighting, such as Dark-type bosses. Actual Fighting-type Pokemon outperform Togekiss at this role, however.

• Hidden Power can cover Fairy’s other type advantages if you luck into a good type.

• For Hidden Power types, Fighting and Bug hit Dark, while Ice and Dragon hit Dragon. However, Charm hits all of the same minus resistances from sub-types.

• Air Slash + Aerial Ace is workable, but Dazzling Gleam is superior vs. Fighting-types.

• Ancient Power, Psyshock, and Flamethrower have no role on offense.

Best PvE Defensive Moveset

• Charm has a huge base power and hits hard on defense against common Fighting and Dragon-type attackers. 

• Hidden Power is generally worthwhile for defense due to its unpredictable typing.

• For Hidden Power types, Fire, Ground, Dark, and Ghost can sting Metagross. Ground Hidden Power is favored as it covers Electric, Poison, Steel and Rock attackers.

• Air Slash is a solid defensive fast move, just worse than the alternative.

• Flamethrower provides good coverage against certain threats and also has the second earliest damage window. 

• Aura Sphere* is a bit of a side-grade to Flamethrower, having semi-similar coverage and a very early damage window.

• Aerial Ace and Psyshock have 3 bars, but their coverage is less valuable.

• Against those who don’t dodge, Dazzling Gleam is by far the strongest.

• Ancient Power is workable on defense, but it’s not notable.

Charm enables Togekiss to deal huge STAB Fairy-type damage without relying on its charge move, though it energy gains are terrible. Air Slash also gets STAB, but is more of a niche since there's many other Flying-type Pokemon.

Ancient Power is generally the preferred option as it pressures Fire-type Pokemon. However, Aerial Ace is cheaper, which is valuable given Charm's very low energy generation. Flamethrower could be used to cover against Ice and Steel-types. The Community Day move Aura Sphere also offers a similar role, being an overall sidegrade in coverage. Regardless, one of those two moves is necessary to prevent Steel-type Pokemon from entirely walling Togekiss. Dazzling Gleam can be used to land a surprise huge hit against unsuspecting Kyogre or Giratina-O, although Charm's damage is often enough on its own.