I'm not promoting any particular coin. I'm asking what alt-coin out there isn't vulnerable to the inevitable 51% attack.
I'm a full supporter of bitcoin, but I will not ignore the fact there is a hole in the Bitcoin system which makes it imperfect.
The attack WILL happen.
First of all, EVERY COIN is vulnerable to a 51% attack, just like your password and cryptogrpahy are vulnerable to a brute force attack. There is nothing that can prevent one. However, the costs of performing a 51% attack are extremely high and it is difficult to pull off. The community will react and come up with a solution, which might just be get more people to mine thus reducing the attackers percent of the hash rate. Also, a 51% attack is not the end of Bitcoin. All the attacker can do is double spend his own coins, attempt to prevent people from spending, and attempt to prevent miners from mining.
Even with 51% of the network, that doesn't mean the attacker suddenly has absolute power and full control. That just means that he has a higher probablility of finidng more blocks and could potentially create a longer valid fork of the block chain. The other 49% of the miners would still be finding about half of the blocks.
In order to actually gain control of mining and adversely affect Bitcoin, the attacker would probably need somewhere upwards of 80 - 90% of the hash rate, which is much more expensive than just 51%.Whatever amount that is, it's peanuts.
If all the major banks came together (Citigroup, JP Morgan Chase & Co, BoA, HSBC, Wells Fargo), they could have the attack done in a matter of 2 weeks. They could put together enough money to take
full control over the blockchain with ease. I wouldn't be surprised if they already have the facilities built and just waiting for the perfect moment to shut Bitcoin down.
The U.S. government..... I don't even have to explain.