None of the alt coins is better in comparison to bitcoins. However, you may invest in some alt coins for diversification. If you do not want to invest in lot of two coins, I will suggest you two coins:

1) Ripple: Ripple is currently available for $0.8 only and it is expected to go to at least $5 by the year end. This gives a very good return to the investors and thus I have invested some money there.

2) Ethereum: If there is one coin which will survive even after bitcoin, it has to be Ethereum. That is why I suggest every investor to split money in between bitcoins and etereum and this will give maximum safety.