When deciding in which coin to invest you can either blindly follow suggestions by others or make your own informed descision based on some criteria:
- What problem does the project attempt to solve?
- Is it a solution looking for a problem?
- Is there active development behind the project? (check Github activity)
- Has the team produced anything but a whitepaper?
- Are there established competitors which are much further into delivering a working product?
- Cross reference developers against previous scam projects
- Current market capitalization of the coin
Thats really a collection of useful points which has to be noted before investing in any coin.
My first choice would be BTC as it has good reputation for over eight years and it could give huge returns.
My second choice would be ethereum which is now performing well.
Thirdly,i would like to buy Decred as i hope its the most under valued coin.
Yet,new promising coins have started coming now and altcoin market would be great in the near future.