Starmie

Starmie was never a top-tier pick due to its frailty, and with every new Water Type it falls farther and farther out of favor. This Pokemon that is supposed to be a star never got its chance to shine, and has fallen by the wayside as one of many fan-favorites that are lost in the shadow of obscurity.

Best PvE Offensive Moveset

• Water Gun paired with Hydro Pump allows Starmie to be Water-type glass cannon.

• Tackle, Quick Attack, and Hidden Power are inferior; lack of STAB, coverage, and DPS make them non-viable.

• Even a Water-type Hidden Power is strictly worse than Water Gun on offense.

• Ice Beam doesn't work well on Starmie, even with Hidden Power Ice-type.

• Psychic is superior to Psybeam, although Starmie is not a great Psychic-type attacker.

• Power Gem and Thunder are inferior, offering neither STAB nor meaningful coverage.

Best PvE Defensive Moveset

• Hidden Power is the preferred fast move for its high defensive DPS and surprise typing factor.

• Psychic, Ice Beam, and Power Gem are Starmie’s only real usable defensive charge moves; the former has STAB and hits earlier.

• Psybeam is inferior to Psychic.

• Hydro Pump and Thunder hit hard and early, but Starmie is far too frail to use them on defense.

Water Gun offers the most consistent performance, and benefits from STAB. Hidden Power can surprise opponents with its unpredictable typing, but has poor energy generation. 

Psychic gets STAB and ties for the least energy cost among Starmie's charge moves. Ice Beam provides useful coverage, including against Starmie's weakness to Grass Pokemon, in addition to costing less energy than other options. Thunder offers superior damage compared to Power Gem, though neither are recommended due to greater energy demands and less preferable coverage for Starmie. Hydro Pump is powerful with STAB, but demands too much energy to use.