You could ask every one of my usual teammates if I rage about champions being OP and they would tell you the opposite. We have our 1 or 2 on the usual team that take care of that for me almost every game, but I don't make comments unless I mean what I say. I'd like to say that I understand how the game works in most areas, so even when one of my teammates dies due to doing something stupid, I will, regardless of sounding like an asshole or a traitor as I am commonly referred to in these situations, explain to them in the easiest and shortest way possible why what just happened to them was not complete bullshit.
There are, however, a few champs that I feel are... imbalanced. Perhaps not in the way everyone might assume, but in the amount of skill it takes to carry out the rape and destruction they leave in their wake. If you're good with a champion and don't make dumb mistakes you should do well, if not break even with the other team. But, there are several champions that take a minimal amount of skill to destroy people with.
I will only mention a few, here, but there aren't many more than what I include; I'm trying not to just whine about them all.
Annie and Kassadin fit the same slot in my theory. They can nuke you at a moment's notice if you get caught somewhere you shouldn't be or during a teamfight. Kassadin gets a bit of a trade-off with a large chunk of his would-be nuke designated as a short-cooldown repeating flash that's absolutely lovely for escaping! One of my routine comments to allies is "Well, he wouldn't be OP if he wasn't fed for the first half of the game." They, of course, agree because that's exactly right, but it's the ease at which they get fed compared to other champs that ticks me off. They prey on the weak and stupid teammates I get queued with.
Master Yi and Tryndamere are in the other slot. Yi is first because I have something slightly different to say about Trynd, who doesn't fit my theory, but I still need to address him. Yi, especially a jungling Yi, is rediculous. Sure, you can stun him to stop him from getting too crazy later on in teamfights, but a smart Yi player will wait until things settle down, whether his own team is winning or losing the fight, then come in and try to clean up the rest. He is a fantastic farmer, so even if your team is losing, he can farm his way to victory using his ult/sometimes ghostblade to escape any danger until it's safe to farm again. The fact that he can almost take down towers faster than you can teleport to them is, in and of itself, completely imbalanced. I don't care what explanation anyone has for it, that should not happen. You may be able to buy some thronmail to deter a fed Yi, but, if he is smart, he can make all of that gold spent on it wasted by going for towers. You can't buy armor for towers and they die fast. The fact that he doesn't have to be doing well in kills to accomplish this is, to say the least, infuriating. The only hope your team has of winning when he is at that point is pushing mid and hoping for the best, but to ensure you pushing faster than he is, it makes sense to leave one person behind that may or may not survive him, making it a 4v4 push mid which still isn't a guaranteed victory.
Now, on to Tryndamere. Granted, he's not easy to play so he doesn't fit the theory, but if you do alright with him until you finish a decent build... I shudder at the very thought. In my opinion, Teemo sucks as a champion and is only good for his mushrooms, but if someone were to play him and he got anywhere near said Tryndamere, he could potentially get- are you ready for this? --> 3-SHOTTED <-- That's right, folks. Three hits from Trynd and he is 6 feet under. I've seen it happen before and I fail to understand how that's even possible.
This will sound very egotistical of me, but usually it's the rest of the team that feeds them. I can't count the amount of games where I've gone 5+ kills with 0 deaths during the laning phase, and as soon as that door slams shut and the next phase begins our team just gets destroyed because they couldn't handle their lanes. There are bad lane combinations. I realize that and have dealt with it plenty, but if that's the case then you either ask to switch or be extremely cautious. I've 2v1'd with Rammus before a few times so anyone who says they can't be cautious needs to rethink their playstyle for at least that single match. I have my bad games. I'm not perfect, and doing well may have something to do with the fact that I main Lux, the uber-ranged slut of Demacia, but some people are just bad.
I should probably just find a nice 5 man premade and STFU so I don't queue with complete retards, but that's not always possible :( I could find a solution to every problem I mentioned (except Yi), but that doesn't help when you have teammates who are just plain bad. A team is a team for a reason, so even if you do what you're meant to do, allies won't always follow suit.
I probably wrote way too much, but I don't do blogs very often so forgive me : )