Even if you only include gym battles and not stuff like rematches or Pokemon World Tournament, every type of Pokemon and every type of move has been used by at least one gym leader.
Pokemon
Rock: Geodude, Onix, Graveler, Rhyhorn, Omastar, Kabutops, Magcargo, Rhydon, Nosepass, Lunatone, Solrock, Cranidos, Bastiodon, Dwebble, Carracosta, Amaura, Tyrunt
Water: Omastar, Kabutops, Staryu, Starmie, Golduck, Quagsire, Lapras, Gyarados, Poliwrath, Seel, Dewgong, Kingdra, Pelipper, Luvdisc, Seaking, Sealeo, Whiscash, Milotic, Crawdaunt, Floatzel, Octillery, Panpour, Palpitoad, Swanna, Mantine, Wailord, Carracosta, Jellicent, Surskit, Slowking
Electric: Voltorb, Pikachu, Raichu, Electrode, Magneton, Electabuzz, Magnemite, Electrike, Manectric, Luxray, Jolteon, Electivire, Emolga, Flaaffy, Zebstrika, Joltik, Heliolisk
Grass: Victreebel, Tangela, Vileplume, Weepinbell, Gloom, Jumpluff, Bellossom, Exeggutor, Tropius, Turtwig, Cherubi, Cherrim, Roserade, Snover, Abomasnow, Pansage, Swadloon, Leavanny, Gogoat
Poison: Victreebel, Vileplume, Weepinbell, Gloom, Koffing, Weezing, Muk, Venonat, Venomoth, Ariados, Crobat, Nidoqueen, Nidoking, Kakuna, Gastly, Haunter, Gengar, Roserade, Whirlipede, Grimer
Psychic: Starmie, Abra, Kadabra, Alakazam, Mr. Mime, Espeon, Exeggutor, Meditite, Lunatone, Solrock, Xatu, Claydol, Bronzor, Medicham, Swoobat, Sigilyph, Slowking, Meowstic
Fire: Growlithe, Ponyta, Rapidash, Arcanine, Ninetales, Magmar, Magcargo, Slugma, Torkoal, Numel, Camerupt, Pansear
Ground: Geodude, Graveler, Onix, Rhyhorn, Dugtrio, Nidoking, Nidoqueen, Rhydon, Steelix, Piloswine, Numel, Camerupt, Claydol, Whiscash, Quagsire, Piloswine, Krokorok, Palpitoad, Excadrill, Sandslash, Flygon
Flying: Jumpluff, Crobat, Pidgeot, Gyarados, Pidgey, Pidgeotto, Scyther, Swellow, Pelipper, Skarmory, Swablu, Altaria, Tropius, Xatu, Drifblim, Emolga, Swoobat, Unfezant, Swanna, Sigilyph, Pidove, Mantine, Vivillon, Hawlucha
Bug: Venonat, Venomoth, Ariados, Metapod, Kakuna, Scyther, Whirlipede, Dwebble, Swadloon, Leavanny, Shelmet, Karrablast, Joltik, Surskit, Vivillon
Normal: Persian, Pidgeot, Pidgey, Pidgeotto, Clefairy (Generations 2, 4), Miltank, Vigoroth, Slaking, Linoone, Spinda, Swellow, Swablu, Ambipom, Lillipup, Herdier, Watchog, Unfezant, Patrat, Pidove, Heliolisk
Ghost: Gastly, Haunter, Gengar, Duskull, Drifblim, Mismagius, Froslass, Jellicent
Fighting: Machamp, Poliwrath, Primeape, Machop, Meditite, Makuhita, Machoke, Lucario, Medicham, Mienfoo, Hawlucha
Steel: Magneton, Magnemite, Steelix, Skarmory, Lucario, Bronzor, Bastiodon, Excadrill, Mawile
Ice: Lapras, Dewgong, Piloswine, Sealeo, Sneasel, Snover, Abomasnow, Piloswine, Froslass, Vanillish, Cryogonal, Beartic, Amaura, Avalugg
Dragon: Dragonair, Kingdra, Altaria, Fraxure, Druddigon, Haxorus, Flygon, Tyrunt
Dark: Crawdaunt, Sneasel, Krokorok
Fairy: Mawile, Mr. Mime, Sylveon
Moves
Rock: rock slide, rollout, sandstorm, ancient power, rock tomb, rock blast, stone edge, rock throw, stealth rock, smack down, rock polish, power gem
Water: surf, brine, aqua jet, water gun, bubblebeam, rain dance, water pulse, hydro pump, waterfall, aqua tail, aqua ring, crabhammer, withdraw, octazooka, muddy water, scald, water sport, bubble
Electric: thunder shock, thunder wave, thunderbolt, thunder, thunder punch, shock wave, charge beam, thunder fang, spark, volt switch, charge, electric terrain
Grass: giga drain, razor leaf, sleep powder, petal dance, mega drain, vine whip, stun spore, synthesis, leech seed, solar beam, ingrain, grass knot, leaf storm, energy ball, cotton guard, magical leaf, wood hammer, grass whistle, bullet seed, gastro acid
Poison: poison powder, acid, smog, poison gas, sludge, toxic, acid armor, poison sting, poison jab, poison tail, venoshock, gastro acid
Psychic: amnesia, psychic, light screen, psybeam, confusion, barrier, psywave, reflect, teleport, kinesis, future sight, calm mind, skill swap, agility, hypnosis, trick room, dream eater, rest, meditate, extrasensory, heart stamp
Fire: sunny day, ember, fire spin, fire blast, flamethrower, fire punch, overheat, flare blitz, lava plume, will-o-wisp, fire fang, incinerate, flame charge
Ground: earthquake, sand-attack, dig, fissure, sand tomb, mud-slap, mud bomb, magnitude, earth power, mud sport, bone rush, bulldoze
Flying: wing attack, gust, bounce, mirror move, air slash, roost, aerial ace, air cutter, acrobatics, feather dance
Bug: u-turn, leech life, string shot, pin missile, signal beam, megahorn, fury cutter, u-turn, struggle bug, x-scissor, infestation
Normal: tackle, defense curl, screech, bide, bind, fury attack, horn drill, scary face, protect, spike cannon, slash, endure, harden, disable, psych up, perish song, recover, rapid spin, swift, sing, body slam, sonic boom, growl, quick attack, mega punch, mega kick, double team, explosion, lock on, supersonic, wrap, constrict, wring out, smoke screen, minimize, self-destruct, double-edge, screech, double hit, swagger, double slap, flash, baton pass, mimic, leer, take down, tail whip, stomp, roar, sand-attack (Generation 1), horn attack, thrash, fury swipes, whirlwind, hyper beam, egg bomb, extreme speed, return, focus energy, encore, metronome, attract, milk drink, mean look, rage, mind reader, headbutt, snore, sleep talk, slam, block, howl, flail, facade, yawn, slack off, teeter dance, belly drum, retaliate, chip away, endeavor, sweet kiss (Generation 3), safeguard, growth, foresight, strength, tri attack, giga impact, odor sleuth, helping hand, work up, crush claw, razor wind, shell smash, fake out
Ghost: confuse ray, night shade, shadow ball, lick, spite, nightmare, curse, ominous wind, astonish, shadow claw, shadow sneak
Fighting: double kick, dynamic punch, karate chop, focus punch, bulk up, seismic toss, arm thrust, low kick, vital throw, reversal, counter, detect, brick break, drain punch, force palm, focus blast, revenge, power-up punch, flying press
Steel: iron tail, mirror shot, magnet bomb, steel wing, metal claw, flash cannon, gyro ball, iron defense, metal burst, metal sound
Ice: ice beam, ice fang, icy wind, aurora beam, mist, blizzard, hail, ice shard, avalanche, ice punch, frost breath, icicle crash
Dragon: twister, dragon pulse, dragon dance, dragon breath, dragon rage, dragon tail
Dark: bite, sucker punch, knock off, feint attack, taunt, pursuit, nasty plot, crunch, torment, hone claws, assurance, night slash
Fairy: draining kiss, sweet kiss, disarming voice, charm, dazzling gleam
I probably missed a few Pokemon and a few moves, but you get the point.
There were way too many sources for me to list them all, but if you want me to verify a specific fact, then I can link you to the source of that fact.
