Here is a good source to decide which altcoin to invest in. I would never buy a dead altcoin with no development except Doge. Doge is unique and will be successful without much development.
Of course we have to choose an active altcoin before investing. At least have adequate daily trading volume. Price is not a problem, low prices can still be considered. Another thing to look at before investing is the developer's level of involvement in the project once it's developed, not a project that's just been abandoned.
I agree on that before investing we need to choose the active project with a active team, and active trading in market, many projects are being abandoned after they collect funds from ICO, so it is also important to choose a good and transparent team.