I followed BitCore development and it honestly seems like it died out long time ago. The chances of it getting revived are small imo..
One project I'm heavily bullish on is Monero. Privacy is undervalued. Once people start looking for it, I really think XMR is going to go quite wild. There's also BEAM, from which people stay away mostly due to the fact that they've set a dev payout for the first 5 years in the block rewards but I think this is a good way to keep those devs pegged to the development of the project.
If you haven't looked at EGLD already, it's also an interesting one imo. The devs seem like they're making a ton of progress.
Privacy coins are good, but they're being constantly de-listed by crypto exchanges due to government pressure. Without government support for privacy coins, I don't see their prices going anywhere in terms of Fiat. At least, they'll survive for a long time because of their decentralized nature. If we were to take into consideration Monero's level of mainstream adoption vs current price, then I'd say it's extremely undervalued. It should've been worth more than $1k by now. After all, Monero is the #1 privacy coin in the world. It's much better than Zcash, DASH, and other so-called privacy coins on the market today. People may not care about privacy now, but that could change in the future once governments increase their surveillance efforts.
As far as Bitcore goes, it seems to me that it won't be going anywhere soon. The project's development progress has stalled lately. There hasn't been major improvements for a while, in order to attract the masses into it. Even with masternodes in play, the coin hasn't soared in price. Interest/demand is very low for Bitcore as most people are focused in the big players on the market. To make things worse, BTX is listed in a few exchanges with low trading/volume activity. If this continues, the project could ultimately die. I've figured that it's not about what shiny new features a cryptocurrency provides, but rather how well it's adopted in the mainstream world. And so far, Bitcore has lacked mainstream adoption at every level.
Nonetheless, I believe there are so many undervalued coins on the market that could become worth a fortune if interest/demand spikes in the mainstream world. You'll never know if you hit the jackpot with the coin you've selected as your long-term investment. One of the coins I'm following closely is Diamond (DMD). The coin will upgrade itself into an innovative platform for smart contracts. With the honey badger consensus algorithm, transactions on the new DMD V4 blockchain will confirm almost instantaneously while fees will remain ridiculously low. The project will combine the scarcity of Bitcoin and the programmability of the Ethereum blockchain. With only 4.38 million coins that will ever exist, I'd say that DMD is pretty undervalued today. At around $2.30, it seems to me that DMD is a bargain. You can accumulate more coins before the "swap" to the new chain begins. Who knows if it becomes extremely valuable in the long run? Just my thoughts