Localbitcoins, but always bring a counterfeit detector if your wish is to convert your bitcoins into cash!
This. If you want physical cash you have to be really careful about a scam at all stages - use LocalBitcoins and:
-Check seller feedback and make sure that they are reputable.
-Meet in a public place to keep yourself safe.
-Check carefully for counterfeit money. If the seller is genuine they should not be offended by this.