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.
I like how THEKEY progress, its seems they were really serious project and also with more real product. Any events that involved with their project always become Announcement, so with that condition, a whole project is very transparent, this is fit with their product on Data Verification