Bitstamp has been my major go-to-marketplace in the past and has so far been very reliable for me. However, they only support a very limited number of cryptos and overall the platform feels a little bit dated nowadays (also if you compare the web platform to Bitstamp's own app)...
After Kraken the best choice. Easy-to-use interface and the seat of this stock exchange is (regulated) in Luxembourg. Unfortunately only a small selection of coins.
Translated from German. Show Original
Nach Kraken die beste Wahl. Einfach zu bedienende Oberfläche und der Sitz dieser Börse ist in Luxemburg (reguliert). Leider nur eine kleine Auswahl an Coins.