Dude, watch this:
https://www.youtube.com/watch?v=ncPyMUfNyVMYou don't understand how Bitcoin and the blockchain works. The amount of computational power you would need to severely disrupt the network at this point is just ridiculous, and they would lose tons of money trying to do so. They would gain way much more money by being good actors. Learn how the consensus algorithm works before you drop your next FUD thread.
Attack or not, bitcoin will be replaced. Lack of development.
Bitcoin could well be superseded in the future but I don't think a 51% attack is what we have to worry about.
As for what other coins could avoid this attack, I'm not positive but I think all alt coins would be if they are being mined and/or just having transactions pushed though by miners.
Edit:
My sister knows a guy who's ex-girlfriend's uncle was a friend of Sataoshi Nakomoto'sHahaha, thats funny shit man, what are you smoking?