I've worked on both conversions and more original stuff so far, but never really finished any one of them yet, since I tend to move on to newer ideas at some point and then just go back to the older ideas later. In short though, I haven't used many 'final' names for my variants, mostly they're just simple conversion names or a suitably kinda-descriptive name for the variant. For reference: I typically ramble and give overly long answers on the internet because I have nothing better to do with my time.
Final Fantasy Tactics D&D - My alternate set of classes, equipment, proficiencies, spells, items, and item creation rules for a FFT-based D&D campaign. Not anywhere near finished, but most parts of it are reasonably well outlined in my documents so far, and a few pieces are finished or very nearly so, while many of the others just haven't been finished yet because of tedium (like checking the FFT stats and features of each weapon, armor, shield, accessory, and other item, then deciding what stats and features to give them in my D&D version).
Final Fantasy d20 - A different setup from my FFT-specific conversion, my FFd20 project is kinda different in basic form and lacks the tiered class system I used for my FFT D&D rules. This one is based more on the normal Final Fantasy games; frex, my Warbringer class is meant to model folks like Cloud Strife, Sephiroth, Steiner, Auron, and such, while I have a Dragoon class to model folks like Cid Highwind, Ward (IIRC the name), Freya, Kimahri, and such. Very FF-based magic systems and races.
Uses limit breaks but I may end up putting in one or two limit break variants that could be substituted in (like Trance from FF9, though I already have something kinda like that factored in; having a full limit gauge provides some minor benefits, but the tension it carries with it incurs some restlessness if the character doesn't spend that pent-up energy in a limit break or a lesser ability; each class has a special ability at some level that provides an alternate use for limit gauge points, though it doesn't expend all of them, unlike an actual limit break; frex, Warbringers gain Limit Strike at one of their middling levels, allowing them to spend some limit points to boost the attack and damage rolls for a single attack). Still working on this stuff.
Magic: The Gathering d20 - My conversion of MTG material to d20 System rules, with an alternate set of races and classes (frex, Battlemage, Taskmage, and Specialist Mage are the three spellcasting classes, while 5 different mundane classes are also in it; mages are differentiated more by their affinities for particular colors of mana and the spells they choose, than they are by class and feat choices; and races include things like hurloon minotaurs, llanowar elves, viscerids, homarids, kyren goblins, cephalids, and such), and a modified spell system based on MTG spells and mana.
Dragonball d20 - Yeah, I've worked on a DB/DBZ/DBGT conversion to d20 rules. I know at least half the people who see this, if any, will certainly have lost whatever respect they may have had for me, or, barring that, acquired a sudden disrespect for me.
Still, I think I did a good job on this at first, and it may yet be a cool mystical-warriors/street fighter-ish/wuxia sort of setup for a d20 game using the basic rules of 3E D&D as its core (just with some definite tweaks to the combat system here and there). I've got 5 different warrior classes that use differing amounts of ki/chi/spirit/energy (frex, Ki Masters have lots of ki development and gain earlier access to Grasp the Sky, while Battlemasters are almost completely mundane with no automatic ki abilities except for Grasp the Sky, but do have the ability to gain ki techniques through feats), and 5 NPC classes that cover the rest of the spectrum (incapable of gaining ki techniques, as those require some PC class levels to represent the rigorous training needed to develop such strange powers.
Universal d20 - My set of slightly streamlined, more flexible d20 rules with a different set of classes for each basic genre, like fantasy, superheroes, modern, and future. Haven't done a lot of work on it yet besides the basic form of the fantasy classes, and basic ideas on the abilities of each. There are some 1-2 dozen classes for each genre (I have 20 fantasy classes set and may add just a few more if I notice any particular gap they don't already fill), but they're kinda simple in form and are meant to cover most or all bases (no prestige classes, or at least next to none, I dunno yet).
Meant to be more flexible, customizable, and simple to some extent, than the core D&D rules (frex, most or all class features are repeated in a static manner, and are either a static increase each time or a new selection from the same set of abilities, which can be repeated infinitely so there is no level cap; example, Runecasters get +1 Caster Level at each level, +3 Arcane Points at each level, a Bonus Feat at 1st and every 4 additional levels, a Runemastery at 2nd and every 4 additional levels, and +1 Lore at 3rd and every 4 additional levels). I really need to get back to work on these rules soon.....
D&D Versa - My simplified version of D&D, meant to be more flexible without too much complexity, by simplifying some elements that are more complex than necessary in core D&D. Only 4 classes, something I'm not generally fond of but the point of this variant IS simplicity after all, and each class has very simple, repetitive features; a proficiency every few levels based on the class (i.e. Fighters get a proficiency every odd level, Experts only get one at 1st and every 8 additional levels, etc.), a feat every few levels similarly, an ability increase every few levels, kit benefits every level or every other level, and for some classes a kit-specific bonus feat every few levels. Each class has additional starting traits that are only gained if taking that class at the 1st character level (such as 4 bonus proficiencies for a character who starts out as a Fighter, among a few other, lesser benefits).
Character customization is pretty broad from these factors, and the kit-based nature of each class' advancement (a Fighter, frex, might start out pursuing the Vandal kit's abilities, then give up his pillaging ways later and start pursuing the Soldier kit's abilities, joining a military and settling down). Spellcasting is made pretty flexible but, for most spellcasting kits, follows the core D&D spell system with just some added range of choices, while some kits may grant a different, unusual kind of spellcasting instead. For most spellcasting kits, they use the core spell system with just a bit of difference; for instance, kits grant only 1st-level spell slots, and the caster chooses each day how many slots to combine into higher-level slots, so they might have a lot of 1st-level spells one day then choose to combine them all the next day into just a few 4th-level slots, if able to cast 4th-level spells. Generally it provides much fewer spells per day than core D&D, unless casting only 1st-level spells that day.
Alterna D&D - No proper name figured out yet for this, I've just been working on it for a year or so. A significant overhaul of the d20 core rules, some parts simplified and other parts just fixed or expanded upon. Frex, AoOs replaced with a simpler 'dropping your guard' mechanic that is brought up by a few actions, and allows opponents to sacrifice one of their next round's attacks to try interrupting you, striking while you're distracted.
Different classes and races, different core setting, different skills and feats, different priestly domains, different epic-level rules, different monsters (many myth/legend-based ones, and some variants on D&D monsters; I really like some of my monsters for this system), different spells and powers, but same basic system (though psionics is very simplified and modified; the Psychic and Maverick classes can gain a few psychic powers, which each grant access to an exclusive psionic powerskill, which is used to generate varying psionic effects; such as Telekinetic Grasp, which grabs, manipulates, crushes, or throws stuff from a distance, its strength and dexterity based on a skill check). Martial arts are largely handled as skills, like Martial Arts (Karate) or the like; I haven't detailed the setting-specific MA skills yet, and don't want to use real-world martial arts styles for it since it'd be kind of unusual for them to be in a D&D setting that isn't based directly on Earth history.
Got a lot done so far with this system, but still nothing quite fully complete yet; I still need to detail a few feats, add a few more to fill in gaps, detail the functions and check DCs for skills (though a few skills are just taken right from the core rules without modification), finish detailing a few class ability options, and finish work on more of the spells (only 1st and 0-level spells are finished, but I still have a few more spells of those levels to add as well). Also, the races need more background info, so they're not quite finished either.
