Are you skipping bitcoin? you look at altcoins and then you're wanting to have a long term goal in this market. If that is so, bitcoin is the ideal choice of yours.
It's been proven by me and the others who have held it for more than 5 years which is your goal. In the past it was quite cheaper but as time goes, you see the progress of it and there's more to its price today which shall increase in the future.
Bitcoin is king because it is king is not a reasonable investment advice. Maybe someone else sometimes knows more than us and understands the specificities better. As long as a person believes to understand the upcoming investment, that is the person knows exactly what it is that it is buying, other coins could also be wise choices.