[Inky]

I'm going to list the main features of the vampires in some of those things to see what the common factors are.

Vampire: the Masquerade.

• Portrayed as fierce, agile predators, but no enhanced strength, speed or senses unless by actively using magic.
• Unaging.
• Sterile (except the 14th and 15th Generation, in whom the vampire traits are most diluted).
• 13 conspicuously different strains ("clans") and many sub-strains, inherited from "sire" to "childe".
• No pulse or body heat, otherwise appear normal (and often more than averagely good-looking), except for one clan who are all monstrously disfigured and a few other exceptions. Retractable fangs.
• Mentally: Liable to go berserk, especially when hungry. Otherwise, by default no different from humans, to begin with, and often obnoxiously cultured and stuck-up. Some are eventually driven insane by the weird and gruesome lives they lead, and one clan are all naturally unstable anyway.
• Created by: bleeding a human to death, then feeding them vampire blood.
• Can't eat people food, at all, it makes them vomit.
• Can feed on animal blood, but need twice as much in that case.
• Special powers: lots, although that's dependent on how much blood they've had. Only one clan can shape-shift. Without actively using magic, senses no more acute than anyone else's.
• Unkillable except by sunlight or fire. A stake through the heart stops them temporarily but they'll get up again if it's removed. Revert to corpses or dust (depending how long dead) when killed.
• Unaffected by religious symbols (usually), garlic, running water, or any of the other fancy things.

Buffy the Vampire Slayer.

• Portrayed as fierce, agile predators; super-strength, super-speed and superhumanly acute senses.
• Unaging.
• Probably Sterile (usually).
• Apparently only one type.
• No pulse or body heat, otherwise appear normal unless fighting or about to drink blood, in which case their fangs appear and their faces go gargoyly - this is a reflex they have no control over.
• Mentally: Psychopaths, to a man, or woman. Explained as due to "having no souls" (this may or may not be accurate, though something magical is definitely going on); care nothing for anyone other than themselves, including each other, will cheerfully kill any humans they can get and not see any problem. In addition to this also have some kind of predator instincts thing going on, even the few freak cases who somehow got their "souls" back, and some are liable to go berserk, especially when hungry.
• Created by: bleeding a human to death, then feeding them vampire blood.
• Can eat small amounts of people food, but it doesn't do anything. (Affected normally by alcohol and drugs).
• Can feed on animal blood.
• Special powers: No particular magic powers and can't shape-shift.
• Unkillable except by sunlight, fire, beheading, or a stake through the heart. Anything else is survivable - one was shot through the heart, went down, but a few minutes later got up again. Collapse into dust when killed (even recently turned ones).
• Repelled by garlic and crosses, no reflection, cannot cross a threshold for the first time until invited.

Twilight. (Thanks to LokRobster. I've only read a comic-book version of the first one.)

• Portrayed as fierce, agile predators; super-speed, superhumanly acute senses and extreme super-strength (crushing car doors by accident almost).
• Unaging.
• Females are Sterile, males may not be but it's not straightforward.
• Apparently only one type.
• No pulse or body heat, eyes amber or black depending on blood intake, otherwise appear normal and eerily beautiful, but, notoriously, sparkle in strong light.
• Mentally: Apparently normal, but most are arseholes all the same. Liable to go berserk, especially when hungry or when they smell blood.
• Created by: by biting somehow.
• Can eat tiny amounts of people food, but compared it to "eating dirt".
• Can feed on animal blood, but prefer human.
• Special powers: Each has one magic power. Can't shape-shift.
• Invulnerable to anything except fire and some supernatural things like werewolves.
• Unaffected by religious symbols, garlic, running water, or any of the other fancy things.

A Discovery of Witches (books). (From memory and a Wikipedia article, and I've only read the first two. If any of this is wrong feel free to correct it.)

• Portrayed as fierce, agile predators; super-strength, super-speed, superhumanly acute senses.
• Unaging.
• Sterile (usually).
• Apparently only one type.
• No body heat and heart beats only once or twice a minute, sharp teeth, otherwise appear normal and more than averagely good-looking.
• Mentally: Mostly normal, but have weird "pack instincts", displaying unreasonable loyalty to certain people. Liable to go berserk when extremely hungry or when they smell blood.
• Created by: bleeding a human to death (or, at least, a lot), then feeding them vampire blood.
• Can eat small amounts of people food, but it doesn't do anything. (They prefer it raw, owing to hyper-senses).
• Can feed on animal blood, and usually do.
• Special powers: When they drink a creature's blood they relive a random selection of its memories. Can't shape-shift.
• Not Unkillable but can survive an awful lot of punishment.
• Garlic hurts their delicate wolfy noses; otherwise, the fancy things don't apply.

I haven't read/watched a lot of the others, can anyone else contribute?