BTC will be the best option for now but it may seem too expensive at the current price.
You can wait for a 50% - 88.2% dip in price and buy as much as you can.

I also think there are few altcoins worth buying and holding.
Honestly you need to do your own research on altcoins because everyone seems to have different opinions.

Factors you can consider apart from technically analysing them could be its adaptability/ usage, volume (market cap),
its ability to troubleshoot bugs and transnational delays, etc. 

I personally hold portions of LTC, ETH, NMC and BTC (not much as compared to the others but will buy back when i sell portions of my altcoins)

Or you can alternatively buy any of the coins mentioned above when prices dip then sell them when it rises considerably.
(caution it can be risky and time consuming.

lastly, you can try trading with or without leverage  (riskiest but rewarding, you will need to learn a lot to do that).
I wouldn't recommend though, unless you know what you are doing.