Buffy the Vampire Slayer

Spike: I love Syphilis more than you.
Syphilis is a cronic infectious disease that is transmitted primarily by sexual intercourse. The disease is generally characterized by skin lesions and ulcerous skin eruptions. If untreated it can cause widespread damage to the heart, brain, eyes, nervous system, bones, and joints. Late stages of syphilis can result in mental illness, blindness, severe damage to the heart and aorta, and death.

Xander: Really? You know, if I'm in the checkout lane at the Wal-Mart I've had the same one.
Wal-Mart Stores, Inc. is a worldwide chain of retail stores founded by Sam Walton in 1962. Based on revenue, Wal-Mart is the largest retailer and largest company in the world. It is also the largest private employer in the United States, Mexico and Canada. $8.90 out of every $100 spent in U.S. retail stores is spent at Wal-Mart.

Harmony: Is Antonio Banderas a vampire?
Antonio Banderas is a Spanish born actor who is considered to be quite the hunk. He also played the vampire Armand in the 1994 film Interview with the Vampire. Presumably this is why Harmony is asking the question.

Spike: Do Melanie and the kids too. Continuing with the idea of turning Antonio Banderas into a vampire, Spike is suggesting that Harmony also bite Melanie Griffith (Antonio's wife) and their children.

Giles: It's the vampire equivalent of the Holy Grail. Legend has it that the Holy Grail is the cup that Jesus drank from during the Last Supper, and that it was also used to catch some of his blood when he was dying on the cross. This cup became an object of great reverence, but was lost in the very early days of the Christian Church. For centuries people have spent lifetimes searching for the Grail including, most famously, the knights of King Arthur's round table. The term "Grail" or "Holy Grail" are now used to mean something that is searched for but is not real or, at least, is never found.