Best Psychic Type Pokemon?

for attacking, tie between alakazam and espeon

defending Gardevoir but mostly because of fairy subtype + fairy charge move, othe than that maybe metagross on defense.

Psychic's effectiveness profile isnt especially good on either front because of current raid bosses, most are psychic themselves so everone's got there coutners ready and psychic resists psychic so they arent effective against raids.

Alakazam with confusion and future sight with a base attack of 271
or Espeon with confusion and future sight and a base attack of 261
vs. common fighting types like machamp you can also use
guardevoir with confusion and dazzling gleam just a base attack of 237 but dazzling gleam deal much more damage than future sight.
All of them are not really got as defenders because of these low stamina and defense stats, but confusion hurts in the first seconds. I often use exeggutor paired with a grass charge move as a defender, because of his higher defense and stam stats and there is no use anymore offensive wise.

Attacking: Alakazam, Espeon.

Defending: Gardevoir. You can also use Exeggutor, Espeon and Slowdudes for walling Machamp but they are easier to counter than Gardevoir.

For atk: Alakazam, Espeon, Jynx
For def: Slowbro, Slowking, Gardevor, Hypno, Exeggutor