As seen in: Castlevania (NES)
Also in: Castlevania: The Adventure (Game Boy)
Distinguishing feature: Helpfully named whip, "Vampire Killer."
Strengths: Killing Dracula, breaking curses, undertaking their manly duties each generation.
Weaknesses: Women named Sonia.
It's not an easy life being a Belmont. Not only do they have to deal with everyday problems like getting the kids to medieval soccer practice, paying medieval taxes and avoiding medieval inquisitions, but they're also forever fated to battle a bloodsucking count with a grudge. Needless to say, there are no accountants in the Belmont clan.
Their only weapon against Dracula is a whip that has been passed down through the generations, helpfully called "Vampire Killer." Simon Belmont is well-known for his exploits, but he wasn't the first, nor the last. Christopher, for example, was kicking around a full hundred years before Simon. And Trevor did his fair share of vampire killing with Dracula's son Alucard even before that.
(There may or may not have also been a woman named Sonia Belmont).
Of them all, Simon is arguably the most popular, while Trevor is considered to be a legendary warrior, even as he worked closely with wall-crawler Grand DeNasty, mage Sypha Belnades, and the aforementioned Alucard. Christopher is a bit of a black sheep by comparison, warranting little mention in the histories to follow. While he improved substantially as a fighter after defeating Dracula the first time, he was never particularly good with the Vampire Killer. At least, not in comparison to Trevor and Simon. Even his trademark fire whip wasn't enough to distinguish him in the end.
Regardless of their eventual notoriety though, whenever the count's castle reappeared, it was up to these brave men (and woman—maybe) to storm the gates, defeat the dark denizens within, and make their way up to the throne room. There they'd engage the dark lord in single combat, with the fate of the world in the balance. Luckily for the world, the Belmonts remain undefeated.
There are consequences to engaging in mortal combat with Count Dracula though. Simon, for example, ended up being afflicted with a grievous curse that forced him to dig up the remains of the defeated Dracula and resurrect him. Christopher had his son kidnapped and turned into a demon during his coming of age feast. Trevor had to deal with Grant. (Sonia was written out of history and may or may not exist.)
But even know the dangers, all of these men (no women to be found anywhere) put their lives on their line with each passing generation, with only a whip, some holy water, random daggers, bladed crucifixes and holy symbols aiding them in the fight against the ultimate evil. Without their willingness to abandon common, non-vampire related pursuits, all would be surely lost.
(Don't believe the lies! Sonia knew Alucard! They knew each other! She was the one who continued the Belmont line! She was real!)
And so the Belmonts will continue the great, manly struggle against Dracula and his dark forces. The world thanks Simon, Trevor, Christopher and miscellaneous for their noble deeds.