I will NEVER use:
A female nidorino/nidoking (technically I should include nidoran-male here too, but that's obvious)
A male nidorina/nidoqueen (above explanation, but for nidoran-female)
A female tauros
A male miltank
A male kangaskhan
A male smoochum/jynx
A male happiny/chansey/blissey
A female tyrogue/hitmonchan/hitmonlee/hitmontop
A male illumise
A female volbeat
A male latias
A female latios
A male vespiquen
A female gallade
A male froslass
A male wormadam
A female mothim
A male cresselia
A female heatran
A male petilil/lilligant
A female sawk/throh
A female rufflet/braviary
A male vullaby/mandibuzz
A female tornadus/thundurus/landorus
A male OR female pokemon that should be genderless