"DAAAAAARRRRRRKNESSSSSSSSSSSS .. "

I'm with the guy earlier. Even when the Noc is on our team, my little heart goes pitter-pat.

Also,

"Hey, guys, we're actually doing pretty well this - "
"LOLOLOLOLCAWCAWCAWCAWCAWCAWCAWCAW .. "

You can't beat the hollow tomblike sound of Amumu's ult, either.

And although its range is short, if you're caught in it, you're beyond screwed. I am of course talking about when Cassie screams in your face and all you can do is stare in horror from glassy eyes.

Karthus and Nunu's

Definitely Nocturne's. When your jungling or in lane and you see the enemy Nocturne ult, you keep wondering who he saw and who he going to get. You wonder if he sees you via ward or if hes trying to gank your team. Either way, you dont wanna move until its over, then you try to help the poor souls getting ganked. Even worse is when the enemy team has a TF and a Nocturne, then, when they decide to ult, you know you are screwed.

That, or Darius'. Cuz you know, that even if you are winning against a lvl 6+ Darius, you are going to lose.

your moms ult

Caitlyn's ult... It seems like she's only ever around when you have no teammates nearby who realize that they can save you by taking the hit.

I was killed by a Caitlyn ult once. My support Taric was at full health and in its path. He flashed out of the ult's way and it hit me (and cue Taric calling me a noob for it).

Gotta agree on Karthus. It's a mad rush for my W whenever that damn beam shows up after a fight

*Sona Player*

Well, one of these depending on conditions given (and of course level of fedness and spellblock)

Darius. Who isn't scared of it?

Karthus unless I can heal out of it and I'm too far away for finishing. Otherwise you just have so long to contemplate your doom.

Cho'Gath. Basically same reason as Darius. Even if it doesn't finish you, Cho is still right there.

Cait ult unless somone is there to tank it for you. Same as Karthus, just waiting for doom.

Garen. Never be low health near Garen. Ever. Unless of course his ult is down =P

Hecarim. Take mega damage and get feared. ouch.

Jarvan (even when he is on my team =P). I keep being afraid, especially with first time players that I will get stuck somewhere I really don't want to be. Something like this =D

Jax. Ouch. (passive, not active)

Pantheon. Especially a fed Pantheon.

Sivir. Just when you think you can get away...

Veigar ult should scare me but it doesn't.

DARKNESS!!!!!!!!!!!!! I hear that I auto hug turret till it ends

Karthus. You know you're ****ed when you see you ALMOST get return to spawn. xD
Cait: ****ed again, same with Karthus.
Noc: Who turned off the lights...where is he?
Darius: SHI--- -Dead;
Galios: FLASHCDFLASHCD. -Dead;
Fiddle: Same as Gali.

Karthus ult.

It always seems to happen right as I'm teleporting back to base.