Although Buffy fights all sorts of evil, she is after all, the vampire Slayer, so here are some of her fangy foes...
Luke was one of the Master's most loyal minons. He fought Buffy in 'Welcome to the Hellmouth' & 'The Harsvest' proving to be very strong. He leeds the Harvest and is the Master's vessel, the one that will give him the power to escape by killing people. Buffy manages to fool him into thinking it's sunrise and then stakes him.
One of the Master's former followers, he cut off his own hand as potence for having failed a mission. It's implied that he's quite strong - he did some nasty damage on Angel - but Buffy finishes him off easily with a broken fence.
Darla, Angel's sire and the master's favorite is plotting to bring her Childe back to the fold - plot which involves Buffy being dead. Angel chooses Buffy pver his sire and stakes Darla.
A powerful vampire and clan leader, the Master despises humans and prepares the return of the Old Ones. Trapped in an underground prison, he manages to escape by killing Buffy. But she's not as dead as he thinks and she manages to kill him before he fully opens the Hellmouth.
The Anointed One
A young child, chosen to be the Master's succesor. He leads Buffy to her death and later plans on bringing back the Master. having failed he takes the lead of Sunnydale vampires until Spike comes in town and exposes him to sunlight, finding him far too boring.
Claiming to have witness the Crucifixtion, this follower of the Anointed One is used by Spike to test Buffy fighting. Buffy stakes him easily and in no time.
This punked out vampire arrives in Sunnydale to cure his girlfriend Dru, and have a little fun with the Slayer. He tries to kill her several times, but always fails. He ends up in a wheelchair, looses Dru and leaves town. When he comes back, he becomes far from evil and eventually even gets a soul.
She arrives in Sunnydale with Spike, weakened and widely insane. Her stay on the Hellmouth brought back her strength, making her a deadly enemy, although Buffy never actually fought her. Before leaving town, she kills a Slayer, Kendra.
Sheila is a disturbed SHS student that Buffy has to prepare Parent Teacher Night with, but Sheila goes missing. On the night, Sheila turns up, vamped and prepares to attack Buffy. But realising the power of the Slayer, she thinks tiwce and runs for it.
A friend of Buffy's from L.A., Ford claims to know Buffy's secret. He is in fact dying and makes a deal with Spike: Spike makes him a vampire and he gives Spike the Slayer. The plan backfires and Buffy gets away, but Spike turns Ford nonetheless. Buffy is waiting over his fresh grave and stakes him a he rises, a vampire.
This cruel, violent vampire was better known to Buffy as Angel, the souled vampire until he lost his soul and reveted back to his old self, tormenting Buffy and killing her friends. As he tried to end the world, Buffy sent him to Hell.
We get a glimspe of Vampire Willow in The Wish and she reappears in 'Doppleganglander' where she takes ove the Bronze with a gang of vampires. Buffy and the scoobies crash in and Buffy pins VampWillow down to the ground, about to stake her, when Willow stops her. She wants to send her evil double back to where she comes from - to be implaed by Oz.
Vampire Xander also appears in 'The Wish' where he kills Cordelia with Vampire Willow. Later, he fights Buffy and ends up dusted.
Buffy's former classmate and Cordette en chef, Harmony is vamped during Graduation, although the others never know. She reappears a few months later and tries to kill Willow. The gang soon finds out that she is Spike's new girlfriend. He gets tired of her and tries to stake her, but she gets away. They date on and off for the next year, as Harmony tries her best to be the big bad, not realising Buffy couldn't care less. She eventually takes off and ends up in L.A. where hse reunites with Cordy. She claims she wants to be a good vampire, but soon ends up part of some vampire sect.
Kakistos is a vampire so old, he skin has become too think for a stake to cut through and has cloven hands. He kills Faith's first Watcher and tries to kill her but she manages to escape to Sunnydale. He follows her there and attacks her once more, but this time she seconded by Buffy and they manage to stake him with a huge pillar.
Mr. Trick was Kakistos lackey, but he took off when things got dangerous. He ends up working for the Mayor but is staked by Faith as he tries to kill Buffy, leaving his job free - for Faith.
An insane vampire captured by the Watcher's Council, Buffy must face him - powerless - to pass the Cruciamentum, a test to evaluate her capacities as the Slayer. She manages to fool him into drinking Holy Water as he takes his pills, causing him to implode.
A loosery pre-graduate vampire that hangs around the Sunnydale UC campus attacking lost freshmen with her crew, Sunday has the bad idea of attacking Buffy. During their first fight she manages to break Buffy's arm and thinks the game is won, but Buffy comes back for more and beats the crap out of her.
The legendary vampire comes to Sunnydale intending to turn Buffy. He seems pretty much unbeatable - with all his crafty tricks and powers. He mind washes Xander and Buffy, but she manages to break free from his thrall. They fight and she stakes him, but he is able to reform from ashes so she stakes him again. No more is heard from him, but he most likely left town asap!