If you're in the US I'd recommend Circle, within the EU you would be best off with Bittylicious or CEX.IO. Bare in mind it will probably take a few days to get verified, once that's done though you'll be able to buy btc very quickly.

Here's a pretty comprehensive list of sites/exchanges that accept credit cards:
https://en.bitcoin.it/wiki/How_To_Buy_Bitcoins_With_Your_Credit_Card