And why? And advertise how fun they can be in ARAMs in 1 phrase.

Mine would be Syndra. Because even if you go 0/15 by the time you reach level 9, planting 6 spheres with your ult on someone and using your maxed out E to stun their whole team and slowly finishing them off with your Q and W while your team picks up the kills, makes up for all the deaths you had.
Potential snowballing.

Oooh, thats a hard question to answer. Unlike most other people, mine is not Lux or Varus or some excellent poker like that. No, I enjoy Maokai, Garen and Xin Zhao. I'm more of a bruiser/tank player, and they are good fun on this map (usually).

That and Kassadin... And Gangplank... And... It'd be far too difficult for me to pick just one/two champions.

I'd very much like to play games as Zigg's: I figure he'd be great in ARAM, he's simply my favorite in general but saidly I have a 1 in 60 chance of getting him and so far no luck

Agree, syndra, though with your range, you damned well better not be going 0/15 <3 I've yet to not be top damage dealt to champions on my team while playing syndra. Get a chalice and spam, get max Q early, watch people get mad and focus you, always take someone out with you with your ult, fun, fun times.

My favorite would be Akali. Yes she can be a bit of a pubstomper but she's so much fun to play here at least until the oracle's start popping up. Dash, burst a target, cloak in the middle and strike at will while your team punishes them for paying attention to you.

Jayce and AP Ezreal for their awesome poke, ridiculous damage and insane mobility. These 2 champions don't need anyone else to do good, so you don't care that much about your team skill.
Now if I have a good team that can back me up, then I also enjoy playing Vi. She also has good mobility and damage, but unlike Jayce and AP Ezreal doesn't have any poke, so she has to really engage, which is dangerous to do alone.

Ezreal, because you can play very aggressively and still escape with e. AP and AD both work very well on this map.

Galio one of the strongest aram champs high burst good ratio high MR team disable

I'm gonna cheat and pick one ADC, one mage, one support, and one tank, because I can't really pick one of those roles over another as my favorite.

For the mage, it's gotta be Veigar. Sometimes the random isn't so kind and puts you against a team without a high-AP caster, but he'll still hit like a truck. I just find him very fun to play overall.

For an ADC, I probably prefer Cait over the rest. And not necessarily because of her large AA range, but more for her Q. It's pretty rewarding to catch somebody with the tip of it, and just see it chunk away their health.

For the support role, Karma. She'll be played a bit more like a mage, I guess, but the AP boosts her supporting abilities. And she also has to focus on getting a lot of CDR as well, to be most useful. Some of the things she can pull off through her obscenely-low-cooldown shield and her sustain, she's a bit of a trollface to play. And I find that highly entertaining.

For a tank, I love Amumu. No real good reason, I just find him fun to play.