Now the market is down. So right now most of the coins are undervalued. If you want to invest in altcoins, you need some appetite for risk. If you have much money then for most secure investment I'd recommend ETH as it's one of the most powerful coins. There are many other coins that have a much greater potential for price growth and much higher growth rates like LTC, RPX, CMT, MTC. I prefer you to do a deep study on the selective one before choosing.