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.

Source:
https://twitter.com/el33th4xor/status/1068856384983363585?s=21dead alts are:
- Verge
- Holochain
- Bitcoin Private
- Pundi X
- Poet
- Decentraland (MANA)
This one would be a great help for those who are looking forward to find a good project to invest in. I became a participant in Pundi X actually and I can really say that it is a good project although it took so much time before I got my token. The value was very high when I sold it and I was able to convert it into large value. I can really say that this list is a trusted one so if you want convenience, try looking at these projects and invest on it and see if you will regret it or not.