Discussing your choices would probably be more constructive than anonymously voting in a poll.
Not going to make any picks, I'm not good enough at the game to have any real judgement of what is or isn't unfair.
You're pretty good as far as I can see ManStuff, especially with Nazrin lately :V
But yeah, explanation for my choices are as follows:
Wriggle: I don't mind her permanent invisibility on the whole, although the recent buff to the timer was not needed. The broken part about her is the fact that her beetles are allow her to farm up so insanely, all the while her permanent invisibility forces the other team to spend money on wards or a Tengu to detect her.
Byakuren: Byakuren has a couple of serious issues. Her first issue, her stunning nuke - not only is it a really strong nuke overall at max level, doing 400 damage to the target and 250 in a 350 AoE (which, by the way, is quite huge), it stuns everything for 1.8s, and with a cooldown of 7.5s its quite spammable. Secondly, there's her ult, which not only makes her a tank and gives her some really strong damage, it gives her insane regeneration on attack, considering it regenerates 60 + 4% of Byakuren's missing HP on each hit she does.
Nue: I've never liked Nue. That ult of hers was just stupid, with 300 (+400% damage if Nightmare in Heiankyo is used) with a 3 second stun in an AoE of 400, at level 3, anywhere in the map where you'd also teleport to. As if this wasn't bad enough, she can level up fast thanks to EXP bonus upon killing and have her skills reset when she kills another girl. Her spear has some annoying AoE and range too, but that's less of an issue considering her cast time on it.
Yuugi: That ult is the only real problem I have with Yuugi. Really, instant kill moves are just lame overall.
Rumia: This one is not hard to see. She has a slowing attack that helps with her DPS and gives her a free critical strike, she's an insane ganker at night with her Midnight Bird skill, and a skill that gives herself some really strong evasion as well as invisibility. And the worst part about Rumia, her low cooldown, low mana costs ult, that will instantly devour enemy girls on low HP (or just squishier heroes outright after a bit of damage) and gain her permanent Strength bonus. It also lets her heal quickly in emergencies or just help weaken an enemy girl. It makes her really hard to put down especially when she has the support of her team mates.
EDIT: Since the vote number increased to 10, I'm adding in my other 5.
Cirno: My problem with Cirno is her proc cooldown of 0, especially considering both passives already have good proc rate, and the frost debuff from Cirno's spells/procs last way longer than they should in my opinion. Next problem with Cirno is how she has such high Agility gain alongside with her high Strength gain, though she may not have any Intelligence gain whatsoever, she doesn't even really need any to be extremely deadly.
Koakuma: Her spells are really strong and she can spam them crazily, even earlier on. I don't really like how strong they tend to be early game, especially due to fact she has enough mana regeneration to spam more and they don't have much of a cooldown. Other than that, her slow is really a bit much when it stacks :ohdear:. But I wouldn't say she's really broken or anything, just sort of bordering that point.
Tewi: Her bombs acting as proximity bombs are really bad, although overall they're not really broken, but really annoying. My main problem is her orb attack. Even if it has a chance to fail, it has a chance to stun them, and the worst part, it does insanely high pure damage. I've seen it take away about 1000 + damage per shot easily and kill most heroes in like 5 shots or so.
Koishi: I really don't think of Koishi as that broken, but her manaburn, free critical strike, free evasion and her really high stat bonus from her ult makes her really lame :V In addition she's really boring to play. That's about it.
Nazrin: I may be the only one who voted Nazrin but... Nazrin I just don't like dealing against. She becomes such a tank with pendulum and its really hard to beat her or anyone with pendulums, since they become so tank and get such annoying DPS. She gets really high DPS thanks to Busy Rod and she can now chase or escape like crazy with the dash. Oh and its hard to stop her from farming well :V those mice are orz, getting point items before me.