It all depends on you, seriously, which kind of good investment can not be compared, the heart of the matter is to see which one to the end of the big gain, but I think this is related to luck, so let it be. BTC and altcoin are all good investment.
Traditionally, Bitcoin does not lose much when the market fall comes. Altcoins lose more usually. However, the tokens also grow faster. Think it over, and make the choice yourself.