I use Coinbase
To buy or sell btc, you do have to link a bank account, but other than that, I find it really easy to use
There is an option to add a VISA credit card to purchase
Where do you live? Because here in the US this site is fine
I highly do not recommend Mt GOX. There are just too many bad experiences with this site
If you're interested in coinbase, please consider signing up through my ref link
https://coinbase.com/?r=522837edffd0e49f60000022&utm_campaign=user-referral&src=referral-link