I have played league for 2 years now and i am satisfied with all my champions, and know how to play most. Yesterday I watched a 
single-handedly penta-killed my entire team, and wondered if she was worth getting. I watched some gameplays of her and she doesn't seem to hard.
So, thoughts?
Also,to every experienced riven players: Does riven get boring? And how many PvP games does it take (approx) to get used to
Riven is very fun but the community will hate you. I had times were a jungler would not gank for me because I was playing Riven. This community has some really bad issues
Yes, do get Riven, she's extremely fun, and having played her for years I can promise you she doesn't get boring. Do not underestimate her skill floor, however.
She takes a surprising amount of time to learn to play well, and despite what the boards might tell you, she falls off late game, so you have to learn to use your time with her efficiently, roaming and pushing and making sure your opponents are constantly pressured.
I had fun playing her back in season 2 (all hail fratmogs), but stopped and went back to Garen for season 3. Even though I no longer play her and reroll or trade her in ARAM I don't regret buying her, and I even got her redeemed skin last season in memory of those old times.
Yes if you can learn to play her perfectly. Seriously tho don't play her as learning her can be hard and the champion turns you into a toxic person if you aren't good with her.
I got a quadra-kill with Gangplank, pre-rework.
And don't be fooled, and don't listen to board QQ, Riven can be hard. An issue that contributes to that is that she is rather binary, if don't win, you will lose. If Riven doesn't immediately get ahead makes sure to stay there, she falls off and becomes pretty useless for the rest of the game.
Does riven get boring? And how many PvP games does it take (approx) to get used to Riven
No one can answer that; That all depends on you, dude.
So "Should I get Riven?"? Whatever you want.
PS: As others have pointed out, for Riven, like Teemo, hating Riven has become some awful Reddit type "meme", so there is a certain kind of individual, existing in depressingly large amounts, that will treat you like crap just because you play the champion.
Riven is extremely fun to play, but shes really hard as well, hard to master in that sense as i'm still terrible at riven after playing her off and on for about a year :P
If you get Riven, you will be hated by 99% of the community. Just warning you.
