I'll be honest, some of these were picked at complete random.
Father: Bardock, Dragon Ball Z. This guy must have some seriously awesome genes considering he's Goku's father in Dragon Ball Z. Even disregarding that fact, he's still a Saiyan warrior whose power ends up far exceeding his low-class stature among his people.
Mother: Itoko Osakabe, School Rumble. This is one of the "for lack of anyone better" options to be honest, especially considering I usually play by the "one character per series/franchise" rule.
Eldest Sibling: Itachi Uchiha, Naruto. I don't actually have an elder sibling since I'm the eldest in my family, so I picked someone who would be very distant for this one. As for the whole "murdering the family" deal, I think even Itachi would have problems trying to kill Bardock.
Middle Sibling: Setsuna Sakurazaki, Negima! She's my favourite character in Negima and...well, yeah. I just stuck her there for the hell of it.
Youngest Sibling: Aichi Sendou, Cardfight Vanguard!! If you've ever watched Yu-Gi-Oh! then describing Aichi is easy because he's basically Yugi (the regular one) with blue hair, no alter ego, and no god-moddy hax. Like Setsuna, he's there just because.
Family Pet: Kog'Maw, League of Legends. OK, Kog'Maw is from a game, not an anime, but he's also a baby abomination from a void-like dimension who devours everything he can find - shouldn't need to explain that one further. For all those wondering why Lord Smugleaf isn't the family pet, I should probably remind you all that Lord Smugleaf is so far above that role, the family would end up being his pets instead.
Teacher: GLaDOS, Portal. Again, another game character, but I couldn't resist. Cake for all the people who complete their tests and do their homework, and anyone who doesn't do their homework gets detention, and then the detention room gets flooded with deadly neurotoxin. No teacher could possibly be better than GLaDOS.
Best Male Friend: Toshiro Hitsugaya, Bleach. This will seem very ironic given that I don't like Hitsugaya much at all, but considering who the other best friend is and what I'm like already (Void-obsessed troll) we need someone who can at least try to keep everything under control, and Hitsugaya probably has the power and personality to do that quite well.
Love Interest: Kurumu Kurono, Rosario + Vampire. Kurumu is a succubus who has the power to charm men into loving her. While I'd certainly dislike anyone doing this to me, I'd probably deserve it for being so utterly ignorant of love as I am. So...yeah, Kurumu gets this position as a means of self-inflicted punishment.
Best Female Friend: Haruhi Suzumiya, The Melancholy Of Guess Who. I'm a massive troll, and while my trolling capabilities have levelled up significantly since high school, I still had a knack for it back then. That in mind, I'd have loved an accomplice to spread chaos and discord throughout everywhere, and who better than Haruhi Suzumiya? Granted, she doesn't do what she does with the intention of screwing up everyone and everything around her, but her ignorance towards the chaos she causes combined with my revelling in it makes for the perfect troll tag team. Besides, she actually proves to be very caring towards her friends when she isn't creating mayhem during her S.O.S. Brigade endeavours.
Rival: Haruki Hanai, School Rumble. I feel that one generally has to respect their rival in some way in order for them to be considered as such, and Hanai is one of my favourite anime characters of all time. The guy is a skilled martial artist, gets very high grades in school, and his personality is serious yet kind, confident yet never arrogant, and honest to a fault (literally - his unwavering honesty is the reason the girl he's in love with is scared of him.) Effectively, he's the polar opposite to my outward personality, so that's why he earns this position even though I think he's an awesome character and a great role model.
Unrequited Crush: Misaki Ayuzawa, Kaichou Wa Maid-Sama! The last in the list is, unfortunately, a "lack of anything better" option so no awesome conclusion to wrap this up...but oh well. Misaki gets this position because many of the male characters she knows like her, some to scarily obsessive levels, and if that wasn't insane enough, it's said her female friends would fall for her if she were male...and she has dressed up as a guy several times in the series. As it happens, her love interest (Usui Takumi) is considered so attractive in-series that every girl in the series fancies him, and even his main love rival admits he'd be completely in love with Usui if he swung that way. So...yeah, she gets this position purely on the grounds that she's this for almost every male main character in her series, and in this case, almost = everyone except Usui.