Okay, here goes my choice of altcoins below $1 already listed on exchanges and coinmarketcap (which I have looked through. There can be many other good project I've not heard about)

1. Electroneum - They are in top 100 but comes in just 2 cents. Though had some trouble initially, they are a working, mineable cryptonight. 
2. Ripple - 67 cents Seriously, I don't like them, but they have an active team with contacts to high level of people in banks. They can make a differnce.
3. Thekey - one and a half cent, they are on a steady ride with a steady project.
4. Docademic (MTC) - 21 cent, they actually showcased their hardware, app and seem to have real contact with doctors and hospitals.
5. Zeepin (ZPT) - 6 and a half cent They are too building their own blockchain, experienced group of chinese.