Put 500$  to coins who has market cap between 20 mil. - 100 mil.
Look Roadmap,  take attention to dev activity,  the part of community, very important thing is markets - where is coin trading (prefer buy coin,  with no major exchanges)

Ofcourse you can make your decision but i offer
             ---> DeepOnion <---
New Android and iOS Wallet
New DeepVault Website Service
New VoteCentral
Latest TOR protocol with OBFS4 and MEEK that allows people anyone to join us
New Commerce plugins will come
New Google Ads
New DeepSend branch
Development Fund With 3 Million Onions
PoS/PoW Hybrid Crypto
Active Community
Bigger Exchanges coming (they just request a full distribution)
Active Developers and Moderators
New Wesbite

Good luck.