The biggest issue in Cryptocurrency today is anonymity.
The only real anonymous technology is cryptonote.
Monero is the best of all cryptonote coins.
For this reason, Monero is the most important altcoin you should invest.
Experts agree with that.
https://bitcointalk.org/index.php?topic=400235.msg6915300#msg6915300(please don't pollute rpietila's thread, don't post anything)
I know you from the Monero-thread. Now its crystal clear why you're promoting Monero right here.

Well, i can understand you.
For me the best altcoins are
NEM, EXO, maybe NXT, too. (without holding EXO or NXT at the moment).