The Lycans are very hard workers. Don't get me wrong, many of the Vampyres are as well, but the Lycans worked much, much harder than they ever did. The Lycans used to be enslaved by the Vampyres, Lucian himself was born into servitude. But he said he didn't hold any ill feelings, he even married Viktor's daughter, Sonja. Viktor, however, feared a blending of the species so much that he killed his own daughter and Lucian was made to watch it. He had been chained but was able to break out of them when he transformed into his Werewolf form, after that he was able to escape out of a window.
The Vampyres and Lycans had been at war for centuries, Viktor (one of the vampire elders) made it seem like the Lycans had started the war, but it was really him. He put blame on them for things he really did. (Like the death of Selene's family). Selene is a Death Dealer and since she thinks that the Lycans brutally attacked and killed her family, she is avenging them. The group she is in, the Death Dealers petty much 'hunt them down, and kill them off one by one'. But like I said she is avenging her family, this is personal to her. But that wasn't what happened at all, and eventually she discovers this.
The Lycans are made out to be the bad guys, but that isn't exactly true. If they did not fight they would not survive. The Lycans were very much underestimated. The Vampyres wrongly believed that the Lycans were very few in number, because they are very good survivors and know how not to get discovered, and because their leader, Lucian, who was thought to be dead, was actually still alive. He's a great leader, and without him they probably would have been very few in number. Selene eventually discovered this was not true as well.
The Lycans are also a lot smarter than the vampyres gave them credit for, perhaps even smarter than them. They were the first to obtain a bullet that was specially engineered to kill Vampyres. This bullet contained concentrated sunlight, which pretty much leads to instant death of any vampyres that is hit with it, the Vampyres then took one of the bullets and copied the Lycans' idea by developing a bullet that contained Silver nitrate. They also developed the skill/ability to change into their Werewolf form at will, and thus are no longer ruled by the moonlight. Which is a big key to their survival also. To sum this up, I suppose you could say the big reason I love the Lycans is because I respect them and all that they did and continue to do to survive.