I’ve been playing Nightlife for the last two days and decided to start my game over fresh, as I was getting too cluttered and disorganized, family-wise, so I decided to start fresh and limit my user-made families to no more than three distinct user-created families per neighborhood, and work with the Maxis supplied families
I started off getting Mary-Sue Pleasant vampirized, after she caught Daniel cheating with the maid, she moved out, changed her name (she goes by the name Mikado Chun now), her Aspiration (Knowledge), and has become obsessed with the “Bite Sim” aspiration, male, female, Townie, DownTownie, NPC, it doesn’t matter, if it’s got a (virtual) pulse, she’ll try to Vampirize it…
give her the Japanese custom hair that came with TS2 (the looped braid with a pair of tiny fans in the bun headdress-thingy), and a dark Kimono and she’s quite the seductive little Vampire Geisha (Band Name!), as Mary-Sue/Mikado appears to carry Maxis’s “Asian” facial structure genetics
Knowledge Sims are obsessed with becoming a Vampire/spreading Vampirism, they also want the Vampires they sire to stay vampires (common Knowledge Vampire Aspirations are “Bite Sim”," <Sim Name> becomes a Vampire", common Fears are “Be Rejected for a Bite”, “Cure Vampirism”)
so, Mikado has built up quite a little coven (group, gaggle, bunch, coven? what do you call a bunch of Vampires anyway? 
) of Vamped Sims, a good mix of NPC waitresses, Townies, and DownTownies, there are now enough VampSims (around a half dozen or so) around that you can pretty much expect to find at least one NPC vampire of some…ahem…“flavour” (pun intended ) at any Downtown lot you go to, the highly elusive Counts and Contessas show up rarely, but there’s enough NPC vamps now so it doesn’t matter
there are quite a few different types of Downtown community lots, city parks, family restaurants, bowling alleys, fine dining, a '50s diner, a high-class (and proccesor-hogging) art gallery, modern nightclubs, gothic nightclubs, clothing shops, shopping centers and grocery stores, there’s a community lot that most any Sim will enjoy,
guess which lot my NPC vampires love the most?..
no, not the Gothic nightclub, good guess though…
no, not the restaurants (although they do like “dining out”, if you knowhatimean… )
no, my Sims are obsessed with bowling alleys, in particular SimBowl, if I take a non-vampirized Sim there (or even a vampire Sim) I can pretty much guarantee that there will be at least three other vampirized NPC sims there, the highly elusive Counts and Contessas do eventually show up, but they’re hard to find and generally aloof towards mere Mortal sims…
after Mikado had done her work, swelling the ranks of the Undead, I decided to make a Sim version of myself, and get him Vampirized (hey, other Sims fans, we *all do this, right, create a Sim version of ourselves in the game, right? )
i send him down to SimBowl, knowing that due to the level of Vampire saturation there, it’s a given that someone will put the fangs to him, he meets one of the Contessas, takes her out on a date, culminating in “Dream Date”, but no luck this time, he’s still mortal at the end of the night
the next evening,the Contessa Stacy leaves him a nice little gift for going on such a wonderful date, the D.J. booth object, and asks him out for another date (no cheat codes used here, there’s genuine Simulated love between Contessa Stacy and my sim)
of course, we go out, this time to the “Midnight Flows” gothic nightclub/bar, as soon as we get out of the car, it looked like Stacy was going to put the bite on him (WOOHOO!!!), but just before Stacy could cast her spell over him, one of the Counts ran up to my Sim and bit him, my Sim had never met the Count, but that Count bit my Sim anyway, oh well, at least my Sim is a Vampire now, I would have rather wished that Stacy did it, but one can’t look a gift set of fangs in the mouth, can one?
(i believe the game sees the Grand Vampires as all one family, so if a sim has any Romance points with a G.V., any other G.V. can bite them, even if they don’t know that Sim)
anyway, we are seated and served dinner by a cute little Vampire waitress (Steffi) that Mikado vampirized, and since my Sim has “Vampirism” and “Fit” as Turn-Ons, he was a little more than interested in her, but he was a gentleman, and stayed faithful to Stacy…
the next evening, my Sim went Downtown to try out his newly acquired powers of Vampirism on some unsuspecting NPC Sims, I sent him to a city park, as it’s the least processor intensive lot and the lack of distracting objects in the game makes the Sims interact with each other more than the distracting objects
my Sim started putting the moves on a rather attractive woman, and by the end of the night, was able to Bite her, fulfilling his “Bite Neck” aspiration
i made the bitten sim selectable, so I could check their Aspirations/Wants/Fears and job…
it turns out, on his first night as a Vampire, my Sim had Vampirized the Mayor of SimCity, who had the Knowledge aspiration and a “Become Vampire” want, and a “Cure Vampirism” fear (and they say politicians aren’t greedy, bloodsucking parasites, eh? ) 
, heh, nothing like going for the gusto on your first try, right, hopefully now that she’s a vampire, the Mayor will introduce some Vampire-Friendly legislation…
the next night, the next Sim that was bitten was in the Law Enforcement career track as a Patrol Officer, she also had the Knowledge aspiration and a Become Vampire want, and a Cure Vampirism fear
the third night, the next “victim” was also in Law enforcement, but she’s a Detective, and once again, had a “Become Vampire” want and "Cure Vampirism fear
I’m thinking of making these previous two Sims playable and getting them to the top of their career track, staring a “Vampire Cops” department (We put the Bite on Crime!), after all, I did download a Police Car to add to the list of available cars** in the game
the fourth night, I found a rather unique Sim, movie star hair, long flowing velvet dress, very glamorous, seduced and fanged her, turns out she’s the “Diva” one of the ÜberSims, top of her career track (Slacker; Professional Party Guest), Wealth aspiration, and GOBS of money, a very high-maintenance Sim, unfortunately, she has a “Become Vampire” Fear, and “Be Cured of Vampirism” want, oops, sorry Diva, maybe you can buy some Vamprocillin-D from the old Gypsy woman, you can afford it after all…
my latest target?, Brandi Broke, as she has a “Be Saved from Death” Want, and what better way to save her from Death than to make sure she lives *forever, right?..
…better watch out Grim Reaper, MacTech’s Vampire sim is encroaching on your territory…
The Sims 2 Nightlife is a really nice expansion pack, the addition of the Vampires really makes the game more addictive than ever) and have noticed a few cool little vampire mannerisms;
Vampires do not cast a reflection in the mirrors
the Grand Vampires, once invited into your house, can enter and leave freely
(** I also downloaded a few other cars for the game, a Ferrari F-40, Dodge Charger, Ferrari Formula 1 race-car, DeLorean DMC-12 (no, not the BTTF version, sadly, and the designer has no plans to make a BTTF version 
)an '06 Dodge Charger, and K.I.T.T.)