Everyone likes making up cards, but most of us probably won't ever see our fantasy cards used in the real game.  These are cards I think could be created for the game if the creators ever think of the ideas.  They aren't in any order, either.    
10. A Giant Trunade for Creatures: I would like to see a card that works like Giant Trunade, only it returns all monsters on the field to the hand.  If it were a Trap or Quickplay Magic Card, it would be very powerful, but even as a Normal Magic card, you can send that problematic Tribute monster or any other annoying monster from the field or kill a whole horde of Spirit Reapers or token creatures.
9. A Trap Version of Harpie's Feather Duster: This would probably be less broken than its Magic counterpart due to the fact you have to set it first, until Executioner Makyura comes out that is.  Less broken equals more playability, meaning there's less of a chance it will be banned.
8. 1900s for some neglected types: Fairies, Warriors and some other monster sub-types could use more powerful creatures.  I would like to see some more beef for warriors besides the new Blade Knight(which I hope I can get), as well as more beef for light monsters.
7. Something based on Imhotep: Not the mummy, the real Imhotep.  This was the man who perfected mummification and designed the Great Pyramid unless I watched the wrong special.  For a time, he was actually revered, and people came to his tomb for miracles, kind of like an ancient Lourdes.  Enough with the history lesson; Since Yu-Gi-Oh! has some basis in Egypt, an Egyptian-based card with a powerful effect(he is a legendary sage after all) would be really cool.
6. Something like Dark Magician of Chaos for Traps: Although Jinzo makes playing Traps less of a good idea and forces decks to limit the number of them, I think it's really cool to be able to get back a Mirror Force, Call of the Haunted or any other Trap to use again.  Although not capable of the one-turn kills the Dark Magician of Chaos can do(which should have been limited here like they did in Japan), the card can get you a powerful card back from the graveyard.  Don't tell me that the card I'm thinking of is Mask of Darkness because I want the same exact retrieval effect the Dark Magician of Chaos has.
5. An Imperial Order for Special Summons: When Mask of Restrict, End of Anubis and Necrovalley won't do, this card will.  Preventing a Chaos deck from summoning its big guns as well as negating other cards like Dark Necrofear, Magical Scientist and many other cards is good.  For those that hate Chaos, this is your card.
4. A Tribe-Infecting Virus for Spells/Traps: If Tribe was bad, this thing may be worse.  It can clear your opponent's field of either Spells or Traps, depending on which you call.  Of course, you would only be able to use its effect once, but you'd know ahead of time what you're up against.
3. More cards like Thunder Monarch Zaborg: While Thunder Monarch destroys a monster and its buddy Ice Monarch Mobius(in the next set) destroys Spells/Traps, it would be cool to see an effect like that with different variations.  Drawing a card, causing a discard and even some burn would be cool just for sucessfully Tribute summoning a Lv 5 or 6 monster.  Cards like this may make more people like Tribute monsters other than the chaos monsters and Jinzo.
2. More cards that attack twice: Hayabusa Knight and Mataza the Zapper have really great effects, but their stats require you play Equip cards.  Make a level 4 with 1500 attack or more within reason that can attack twice.  A 1900 with the attack twice effect isn't broken due to the number of played monsters that are most likely to be on the field such as Spirit Reaper, Archfiend Soldier, Berzerk Gorilla and select others.  Some cards though would need to beware.
1. More cards based on Mythical Heroes: Upper Deck really should have kept some names the same, like Airknight Parshath being Perseus in Japanese and Ha Des being Hades(BTW, Hades has nothing to do with Satanism as Hades was king of the Underworld which had Heaven and Hell in the Elysian Fields and Tartarus according to Greek Mythology).  Hercules's card could be self-powering, while one for Thor(not the Marvel character) could hit all monsters with his hammer.  I'm a huge fan of mythology, so I wish Upper Deck would grow a set and publish cards from other mythologies.
       If any of the card ideas I have up there are already in Japan or anything is amiss, such as that stuff on Imhotep for all the history buffs, or anything else, e-mail me at zeno9d9@aol.com.  I like card ideas, too, so if you can name my cards, great.  Thanks a bunch.