Most reliable exchange in Europe is bitcoin.de . It's very secure, customers are very satisfied for nearly three years - no hacks, no un-announced pauses, no delayed withdrawls. bitcoin.de is compliant with german law, the ceo is well known in the bitcoin-scene and beyond as a founder and businessmen, bitcoin.de persuaded the fidor bank to cooperate with bitcoin-companies, the support is famous to be fast - so yes, there is at least one really reliable exchange already.
I hear only good feedback about bitcoin.de lately. I think I should try them. There must at least one reliable service.
but please be aware that on bitcoin.de the trades are directly person to person. the exchange just keeps the btc in escrow. no fiat ever is transfered to the xchange itself.