This is an argument I hear from people who don't understand a lot of things about this game. First off, most people that think Riven is broken think that the way to win the game is kills, cs is nice but not necessary if you have enough kills to make up for it, and don't understand how to play safe.
All you have to do to beat riven is not fight her. Counter-intuitive, I know, but think about it: if you engage, you lose. If you trade, you lose. But riven sacrifices a lot of you force her to farm with her abilities. All you have to do is stand back and punish her for farming, preferably while not jumping out into the open and being an idiot. Here are some champions that should be able to deal with Riven fairly well:
His knockup can zone her out of CS, by making her stand back and wait to avoid getting knocked up and taking damage. His silence can actually help you trade with Riven because her mobility, shield, and stun all become useless if she tries to go in on you. When you see her jumping at you, silence her and punish her with your spikes, or use it to land your q, if you're lucky.
His silence is on a pretty short cooldown and is good harass when Riven comes in for CS. You do damage, and nullify her abilities. Very useful for keeping her at bay. Your sustain and abilities can also make the laning phase hard, as out trading a Garen, if the Garen is playing correctly, can be worthless with his health regen passive.
Has the tendency to be tanky and have lots of damage, and he has a root. Slap this thing on Riven, and she becomes mostly worthless. When you see her charging in to dive you, slap her with the Rune Prison, and out trade her. You also have a range advantage. She can dive over your back line, but after that, it's all in. She now draws minion aggro, and can't run too far before you can possibly out trade her. Just stay back far enough to be safe, and she will have nothing to say to you.
Annoying as hell, and his blind makes Riven mains want to die inside. Not to mention, his poison can be applied from a safe distance. As well, punish Riven for trying to jump on you by making sure there is ALWAYS a mushroom in between you and her, so that she can't jump to you without taking a bunch of damage, eating a slow, burning her escape, and generally getting out-traded, when you consider that you should have your blind on standby until you have established dominance in lane, after which you can deny her farm with it until she's so frustrated, she'll dive you or afk.
Has ungodly sustain, and an escape that is almost as much bullshit as Fizz's Playful/Trickster. Whenever Riven tries to trade, just pool when you see her jumping for you, and then lifesteal off minions. You have range on her, so stand back, keep yourself healed up, and if you can without dying, poke her when she farms. If you take away her kills, she has to farm. If she can't do that, you win. She becomes totally weak and useless.
Overall, it seems you have a mindset problem about Riven; from how you talk about her, you seem to be thinking only of how to kill her; you don't want to try and do that. You just want to push her out of lane, mess up her farm, and most importantly DON'T DIE. ABOVE ALL ELSE, DO NOT DIE TO RIVEN. That means standing back and being annoying as hell. Most people have problems because they push the wave whenever they farm, and it makes them susceptible to jungle ganks. Next time you see a riven, try to stay as far away from her as possible and only farm. If your jungler wants to kill her, save your cooldowns and lock her down, make sure she dies. Also make sure the minions are pushing towards you if you're going to try to kill riven with a gank. Until late game, never try to kill a riven without help. She excells at 1 v 1's, and you should try to avoid this at all costs unless she is so weak from lack of kills and farm that she can't hurt you.
one of the first items rushed, taking that off the weakness list pretty easily
, so basicly this argument is, dont play any champ but 1 of the few insanely stong top laners.
pretty much takes the squishy right out of her, + her shield on a what 5 sec cd? So im supposed to bait out rivens shield? well if you assume the 2 are on equal skill lvl then the opponent wont be able to bait out rivens shield all the time, and odds are she is casting her shield in a retreating direction so there is little to no follow up after the shield wheres off.
basicly ignoring armor. So still not a good enough weakness for all the strengths she has
or 
you should be fine
have no waifu pillows.... yet I may get one at comikaze on haloween BUT until then you sir or madame are incorrect.
counters her or I just got lucky. 