Bitcoin is and will still be number one for a long time, even the current coins that look promising like ETH and Monero are very unlikely to take it's place right now, considering their prices as well as actual use is very much less than BTC regardless of their rise of price due to speculation.
Monero might not bet the one that replaces the ranking of Bitcoin from the number one spot to the number two spot. I would prefer to use Maidsafe or MAID instead of Monero just because the people that help develop that coin know that they have to test a bunch before releasing a working product.