This video shows the inherent problems this trope makes with creating any sort of Intercontinuity Crossover with more than one series that includes a vampire. In a very humorous manner.
As mentioned above, Gaia Online vampires do not die in sunlight. They just get really sunburned, really easily. And sometimes catch fire. They do still need blood though, but can subsist on human-style fare (though they find it unpleasant) or soy-based blood substitutes. Also, (as Louie is quick to point out), they do not sparkle. Stop asking.
zOMG! also has vampires as enemies in the recently opened area, Deadman's Shadow, which are unconventional even by Gaia Online standards.
Eddie Izzard has a bit (about 0:50 onwards) about vampires, and the tendency of directors to "change the rules".
It's more of a metaphorical lesson on power-hungry humans, but Fred Clark does pose an interesting idea as to why vampires fear crosses in this blog post.
skary.net, the website of Katy Towell brings us the Mockingbird Song, an animated short about a girl named Shawnee Jenkins. Her parents are attacked and bitten at some point. They eventually turn into feral vampires. They degrade to the point where they're basically animals, unable to even speak. Yet Shawnee continues to care for them and clean up the messes they leave behind. They're still her parents after all.
Most recently, a sequence showed what appeared to be a sentient vine that attacked two girls and turned them into vampires.
The lamia of Unsealed and Blood News are: living beings that start off by stealing the victim's voice and a piece of their soul which they only return when the bite comes and the blood is taken.
Eddie from The Insane Quest is an odd case, having nearly all the weaknesses of a traditional vampire and none of their strengths (except when under the influence of his Super Powered Evil Side). He can survive on a diet that does not contain any blood (though the smell of it causes him to go into a shark-like feeding frenzy) and can withstand mild doses of sunlight but temporarily disintegrates when exposed to high concentrations of light. Since no other vampires have appeared in the series, it is unknown whether all vampires in his universe share these attributes, though it is implied that he is a weakling by their standards.
Vampires in Chaos Fightersdo not suck human blood. Their blood, however, is useful to prevent bleeding in small amounts due to blood clotting effect on human bloods.
This video showcases information gained from the accidental creation of a "real" vampire through gene therapy. Most of their traditional weaknesses don't even exist (garlic and holy water don't work, sunlight just hurts their eyes). The ones that do act different (right angles like crosses cause them to have fatal seizures because of the way their brains are wired). They also feed primarily on human flesh and only drink blood as a last resort. Oh, and they're now extinct because of the right angle-laden structures our ancestors began to build.
The vampires in Blood Light are pretty much your typical broke-ass urban twentysomethings. Or at least they look twentysomething. Some don't even have fangs.
The "vampires" of Orion's Arm were goths who programmed their genetic tweaks and life-extension bionano to include sensitivity to sunlight and a need to drink hu blood. Most polities can easily cure them when discovered.
Night Hunters. The vampires in these books, accumulate resistance to sunlight the longer they live, can live practically eternally, unless killed, have no weaknesses to garlic, or individual religious objects, cannot be killed unless with silver through the heart or beheading, don't evaporate once killed, burn a pint of blood every six hours and can turn into near 9 feet tall armored monsters with a split lower jaw.
