There is no such thing as "most interesting", it depends on what you look for (technical quality, investment, compatibility, etc), what you need (bleeding edge, stability, doc, popularity...). Plus it's hard to assess innovation, some coins may very well be genius and we are not visionary enough to know.

Some characteristics to look for:

- ASIC resistance. Some currencies make sure you can't just throw money at GPU and become the king of the hill like with Bitcoin. E.G: Vivo, VTC, XMR.

- CPU friendly. Some currencies can be mined on CPU, not just GPU. It makes it interesting for embedding in web pages or viruses. E.G: Monero, Aeon, etc.

- Privacy focused. Some currencies make it hard to know where does the money comes from and goes to. E.G: Monero, Zcash and co.

- Smart contracts. Some currencies are not just money, but gigantic programmable public databases. Ethereum being to smart contracts what bitcoin is to cryptocurrengies in general.

- Master nodes. Some currencies provide very fast transactions by featuring nodes responsible to pre-validate them. E.G: Vivo, Dash.

- Community. You may want big name supports (Bitcoin, Ripple), great tooling (Ethereum, Monero). You should check if your exchange deal with the currency your target.

Personally I like:

- Vivo. The team is close to home. The master nodes give me great rewards and I help friends and family to setup theirs, for a fee. Best investment to date, appart from BTC. But only cryptopia deals with them which make it hard to trade.

- Monero. Simple to mine, and nobody knows what I do. But a bad rep because of the viruses.

- Ethereum: it's the most stable currency IMO, because of all the ecosystem, it's not gonna die. Also awesome team. Very little downside to this one.

- Ripple: big names trying to do official things. I'm curious of the result. But it's premined.

Sometime I feel like I should stop writing blogs post about Python and be paid as a full time crypto explainer, cause it's like I answer the same questions every day.

Anyway, good luck. And don't believe any people telling you they perfectly understand this market, because it's the most irrational one I ever seen. It's unstable. It's exploding. It's crazy. And so fun. Until you loose everything :)

> ASIC resistance ... make sure you can't just throw money at GPU and become the king of the hill; CPU friendly

first of all, asics are specially designed hardware, not gpus

second, switching to actual gpu- or cpu- friendly algorithm comes with it's own drawbacks - anybody controlling large enough botnet can perpetrate 51% attack against you