When I was playing good old blue version, I never did. Then when it got to later versions, I tried to nickname them all. Now I usually only nickname ones that are important to me. I try and put a lot of thought into them, because sometimes I think up personalities to go with them, and make them sort of like my own characters. I'll draw myself with my team and everything. Anyway, here's some:
Arcanine M:
Jerome (After a character from my favourite anime Ginga Densetsu Weed)
Kai (Me and my SO are respresented by our fav pokemon in game)
Lucario M:
Raoul
F:
Rei
Entei:
Lloyd (After my late grandfather)
Charizard M:
Li
Nidoking:
Thijs (A dutch name pronounced "tice", I knew a kid once with this name and I just liked it)
Feraligatr M:
Kensei (Means "power" in japanese)
Hachi (This was my happy-go-lucky partner in mystery dungeon)
Raichu F:
MeiShurrai ("blue thunder", a character I created when I thought up a design and personality for my pikachu in yellow)
Ninetales F:
Kara (after my SO)
Karma (Suits her, no?)
Houndoom M:
Kurt (A shiny houndoom is blue, and the spaded tail reminded me of Nightcrawler from X-men. People think of him as a demon as well.)
Mightyena F:
Raksha
Tomoe (female warrior, and a character from Rurouni Kenshin)
Granbull M:
Goliath (After that one character from that old old show Gargoyles.)
Rayquaza:
Sultan (like King, but less common)
Blaziken M:
Kojuken (random)
Blastoise F:
Maelstrom (it's a sea storm.)
M:
Kain (my faithful partner from mystery dungeon)
Swellow F:
Roena (Random, sounded good)
Zapdos:
Taranis (random, sounded good)
Moltres:
Kesaikou (something like "flame prince" i believe)
Articuno:
Cobalt (it's a shade of blue, also the name of my late budgie)
Altaria M:
Tyltalis (random, sounded good)
Infernape M:
Dakam (random, I wasn't trying real hard. I didn;t like any of the starters for this gen.)
Floatzel M:
Enerjak (sounded good)
Alakazam M:
Eisenheim (main char from The Illusionist)
Luxray M:
Koji
Voltaire
Dewgong F:
Mhera (A redwall otter)
Zangoose F:
Spartina
Deidre
Seviper M:
Katana (I looked at the blade on the end of his tail and it stuck)
Meganium M:
Hemlocke (Poisonous plant)
Scyther M:
Sutoraiko
Shuckle:
Chuckie (I couldn't help thinking of this name when I heard shuckle. Chuckie the shuckle. Something made me think of Chuckie from Rugrats)
Venasaur M:
Oleander (another poisonous plant)
Quilava M:
Magumarashi (His Jap name which really appealed to me for some reason.)
Typhlosion M:
Kaen
Machamp M:
Miyagi (like Mr.Miyagi from the Karate Kid)
Venomoth M:
Viktor
Grovyle M:
Enrique
Sandslash M:
Miles
Tropius M:
Seraus
Absol:
Kataclyzm (corruption of the word "cataclysm", which is a disaster)
Skarmory M:
Skyver (sounded cool)
Rattata:
Remille (Played with the name "Remy", I had just seen Ratatouille)
Mudkip M:
Skipper (One of my less original ones)
Cubone M:
Misuteri (Thats what one japanese dictionary said was "mystery" translated. I thought of that because I was wondering what cubone's head looks like under that skull.)
Uxie, Azelf and Mesprit:
Gakuryoku, Kiryoku and Jouryoku respectively.
("Ryoku" is power. "Gaku" is knowledge, "ki" is will, and "jou" is emotion. Because they are the beings of knowledge, willpower and emotion.)
Dialga:
Shiganai (Sounded cool)
Kyogre:
Muzaku (Sounded cool)
Latias:
Cheyenne (I believe it was the name of a native tribe)
Cresselia:
Selene (moon goddess)
Phione:
Tsunami
Giratina:
Invurse ("inverted" and "universe")
Nidoran F:
Syren (like "siren", I remember reading a pokedex entry somewhere about it calling...)
Ninjask M:
Jutsu (I'm not a huge fan of Naruto, but it's to do with the show, and they're ninjas)
Rapidash M:
Kajinn
Flareon M:
Jakkei
Vaporeon F:
Umi (I believe its some sort of water demon/goddess/thingy)
Jolteon M:
Takasu
Umbreon F:
Drakkuna (I probly threw some words together)
Espeon F:
Aurrah
Golduck M:
Lu-Kar
Lapras F:
Nefereti
Gyarados M:
Arkos (Means "king" in some language or another...)
Kabutops M:
Pheenux (corruption of "pheonix" because the fossil pokemon are ressurected)
Aerodactyl M:
Kohaku (Means "amber" because they were ressurected from "Old Amber")
Starly M:
Twink (I don't like starly and I thought it sounded like something mildly annoying. It's a WOW term of some sort I believe as well.)
Fearow M:
Tyrant (I thought of that episode where the fearow was scaring the pidgey)
Kecleon M:
Meerage (corruption of "Mirage")
Smeargle M:
Vinci (Like Leonardo Da Vinci)
Tauros:
Mynos (From "Minotaur", a mythical half-bull half-man)
Electabuzz M:
Taz (Like the cartoon tasmanian devil, dunno why I associate electabuzz with him)
Pachirisu F:
Teekah (Sounded like a squirrelish name)
Ghastly M:
Omen (A sign of bad luck)
Pidgeot M:
Artemis (The pidgeot names are names of hawks I've worked with at a local wildlife centre. It might also interest people to know, since Artemis is a somewhat common nickname for male pokemon/pets, that Artemis is the greek goddess of the hunt.)
Major (Short for "Major Attitude." A harris hawk. )
Misko (Means "red" in Cree. Was the name of a redtail hawk.)
Mewtwo:
Legion (I believe it's the name of a demon)
Seigfried (My fav Soul Calibur Character)