If I planned on buying some coins today. Which would be the better long term investment, and why?
Its depends directly on how much money you have. If you have now a pretty substantial amount, I should say: invest on BTC, for its price is low now and you can earn money in a short time.
If you don’t have a lot of money and you want to make a tiny invest, maybe you should choose an altcoin, as Dogecoin.
There is also a third panorama, the intermediate one, where you have money enough to buy an important altcoin, as BTC Cash or Ethereum. I would choose this option If I had enough money or if I had a lot of money and didn’t want to spend it all.
Those three options are good enough to see substantial profits anytime soon.