LocalBitcoins. ID verification is required, which some see as an issue but although bitcoin transactions can be traced to and from, there is no trace linked to what you purchase with it. You "just sent someone some bitcoin".
After registering and confirming ID you can purchase bitcoin from a multitude of sellers using various payment methods. I'd suggesy using faster payments.
When you open the trade, you'll receive the account details of where to send the money. Bitcoin is usually received within a minute or two of sending the payment. Your transaction is also protected by escrow, the bitcoin you purchase is held by them automatically until the seller confirms payment. Many of the sellers use bot accounts too so, assuming your payment was made correctly, the bitcoin will be released almost instantly.
You can buy bitcoin at a fairly reasonable price when it's not in the process of skyrocketing and the sending fee fluctuates between £1-2.
On average the whole thing costs me about 3-4% in fees after actual market price of bitcoin and sending fees are taken into account, but that will vary depending on how much you buy at a time.
Another little plus is that, once you have received your bitcoin from the seller, your tiny sending fee is added to the bitcoin amount you are sending to the vendor without you having to work it out and add it on and account for fees blah blah, and it's clearly outlined on the page how much the fee is separately. You only have to send the exact amount that you need to pay without having to think about adding the mining/ sending fees afterwards as I hear a lot of others have to do, hence all the "tip jars" on vendors pages for short payments.
Hope this helps