Personally, i use campBX. haven't had any issues so far.
You must not have visited the site lately. CampBX has lost all ability to transfer to fiat. [Edit: It didn't occur to me at first but CampBX is probably great for buying bitcoins, just not for selling and cashing out.]
Coinbase is great.
Localbitcoins is crawling with law enforcement looking to bust unlicenced exchangers so don't offer your coins or cash as a business or service, only for your personal purposes. I am just staying away from there completely.
MC