If you look for alternatives you should look at the technical differences. Where BTC has been quite stagnant on that front, some altcoins have faired way better. Take a look at NXT for example, tons of projects are being build on that. There are plenty of others too. SYS is building a decentralised exchange. Vericoin has a very cool wallet. HYPER is aimed at gamers and pays 5%/month interest for PoS. And some countrycoins are doing well, most notably NLG and Sterlingcoin.
People here say that BTC is the one and only. Very understandable. But does anyone stop to remember MSN? Or MySpace? BTC needs to keep reïnventing itself or it will be replaced by something better. It's the blockchain technology that really is the breakthrough, not BTC itself.
Read the white paper again and wiki:
https://bitcoin.org/bitcoin.pdf
https://en.bitcoin.it/wiki/Block_chain
You can't separate the two, they work in conjunction with each other, and because of each other.
There's no blockchain without Bitcoin, and vice versa.
Excuse me, I could have chosen my words more precisely. Where I used the word 'blockchain' I ment 'a public ledger with a certain set of algorithms governing it'.
In my defence, most people refer to those ledgers as 'blockchains'. I will even go so far as to contend that the public use of this word will replace the meaning that you quote from the Bitcoin wiki, where it refers only to the public ledger that underpins (or: is, in a sense) bitcoin.