I think, Bitcoin is the best to invest because it still remain the king among other cryptocurrencies which it will allow you to enjoy some reward in your investment when the price increase higher. Now that the price of Bitcoin has decreased to 24,182, showed that you can use any amount of money to invest in Bitcoin and hold to watch when the price will increase higher to your satisfaction before you can sell to experience what other potential traders are experiencing in the community. I believe, you will not regret why you invest in Bitcoin, because whenever Bitcoin price is pumping in the market other cryptocurrencies price will be pumping too, showed that Bitcoin investment is a profitable investment.
I agree, bitcoin is by far the best one and will stay the best one and investing into it would make you the most profit. However, if we are in altcoin section and I am forced to pick an altcoin to pick, I would have to pick ethereum because then we are talking about altcoin in that case, even though it is second ranked and bigger than most coins combined, it's still an altcoin, and I believe that it will definitely be staying at a high level and not going anywhere anytime soon.
In that way, you are investing into something because iti s highly ranked like you would on bitcoin, but you are still picking an altcoin at the same time. Bitcoin and ethereum, they are just too good to not pick.