Gold companies have been very hit and miss over the last 12 months. eg. NST at all time highs while RSG was recently at 52 week lows. Also there's been single mine companies like DRM (now down to 1 mine), BLK, MOY, WPG struggle in 2017. And there's been political risk in many countries overseas like Tanzania (changing tax rates) and in SE Asia.
So I'd say the lower risk companies are those operating in good juristictions like Australia those companies that have multiple mines (to diversify operational risk).
Saying all the above, I have like RSG, RMS, SLR which have been undervalued more recently. Also been impressed with EAR's drilling results over last few months (NST recently bought some 16.4% of EAR). AMI recently became a 2 mine camp operation as well around Cobar, so could be worth watching.
On the exploration side I have liked BRB and KIN (now a developer). There's also a bunch of very high risk plays drilling deep diamond cores looking for gold-copper phyrophery deposits.
I have traded, or continue to trade, some of these companies mentioned. Please do not take as recommendations. Each company has different market sentiment and outlook. Some are much higher risk than others.