Things that make you just shake your head...

*Out-damaging your ADC... as support.

*Out-damaging the enemy Nasus... as support.

*Warding more than the support... as a top laner.

*People not leashing for junglers... then the jungler going for red/blue buff without leash... and dying.

*When you successfully shield your teammate's escape... only for them to run back in and die.

*Your team leaving you to defend turret... as support... when at least 2-3 of them are nearby, more focused on kills than objectives.

*When your teammate says "warding is the support's job" when you stress the importance of warding.

*When you go from a nice, easy champ select to half your team trolling in match, causing you to nearly lose a match that started as a 5v3.

*Teammates saying "let's do baron" when the enemy team is fed, you're down a teammate, and all of them are up.

*Junglers who say they're coming, only to sit in a bush and twiddle their thumbs. Bonus points for when you're Sona and he just sits there as you ult two of them under your turret.

*People who won't shut up about how Teemo "counters" Garen, even when you cite your 9-3 record against the Little Satan.

*When you're trying to lobby/beg for a role in champ select and somehow you winning 70+% of your matches with a particular champion in the last 30+ matches with a KDA of over 7 isn't enough to sway them from taking the role you want (and that they're awful at) because "that (AKA winning) doesn't matter."

*Accidentally ulting/flashing/etc. The worst of them all, though, is when you somehow TELEPORT by accident... to the turret you're standing right next to. I've done that. Don't know how, but I have.

*An uber fed Master Yi in co-op stealing over half of your blue buffs when you're jungling. Including stealing the enemy's blue buff when your teammate points it out.

*Nervously button-mashing with Sona in sticky situations and coming out with a double kill. I have more double kills with Sona than I'd like to admit.

*Igniting someone specifically to secure the kill for yourself, only to somehow lose it to someone else.

*When you recall after having just won a team fight and, by the time you're back, your entire team's been killed because they overstayed their welcome and you weren't there to bail them out.

*Basically, anytime someone besides me goes top. I loathe nearly everyone who does. Why? I might be overly critical as I main top, but it's rare that they don't make me die a little inside, largely because practically nobody in bronze, top lane or otherwise, seems to know how to play from behind. I start 0/3 thanks to Voli camping Riven's lane for her? Finish 10/7/10, the only positive one on my team. That was my worst match in WEEKS, at least, and I still finished with a KDA of 2.86. Only been under 2 once. But about half the time someone else goes top, especially if they fall behind early, they're lucky to manage 1:1.

*When you buy three mystery skins and one has the worst splash art you've seen and is for a champion you own but have never played (Sivir; Spectacular Sivir), another is for a champion you hate (Dr. Mundo; Mr. Mundoverse), and another is a lame skin for a champion you only play when circumstances force you to play ADC, which is almost never (Caitlyn; Resistance Caitlyn).

I'll stop there.