About the altcoins to hold in long term, I can not give you an advise on it as ethereum only a little went above the previous all-time high and fell back to the price it is today.
Take gold for example, gold was way in existence before Bitcoin came into play, but the value of Bitcoin has beaten gold tremendously.
You mean price and not value. If you are referring to market value, no assets like gold as it has the highest marketcap in the world. But in price, due to very low marketcap of bitcoin to gold, its price surpassed gold price.