Coinbase lets you buy Bitcoin, Ether, Litecoin, which one should you Buy

Coinbase allows you to buy Bitcoin, Ethereum and Litecoin, so which one should you buy?
My advise is to buy all 3, in order to diversify.

When I first got with Coinbase I started buying only bitcoin, back when the price was $800, and Ether was $8; however I was solely focused on bitcoin that didn't buy Ether because the price had been so low and I didn't think it would go up,
and missed out on some of the early gains.

After seeing the price of Ether jump to $40 I got in and started to do my research on Ether and realized that I could go much higher, and it did. It went over $400, but has recently dropped to $300 which is still several times higher than what I paid.

So then as soon as Litecoin was added to Coinbase, I decided to buy some, since it shares similar characteristics with Bitcoin, I see that this coin has future potential.

All 3 of these have gone up in price, so by diversification I haven't missed out on gains from other alternatives to bitcoin, although Bitcoin makes up 70% of my wallet.

If anyone is interested in getting started with Coinbase here is a referal link, When you buy $100 worth of bitcoin both you and me will get $10 worth of Free bitcoin.

https://www.coinbase.com/join/585c98033f676a02709ccab9