I'd say Bitcoins, but Paypal has more "audience".
There are much more people that using Paypal for payment instead of Bitcoins, it's like Paypal is more "user friendly"
In time this will change. PayPal only have the gain over bitcoin due to them being the first ones to break into the online payment processing niche, while bitcoin (or I should say blockchain due to blockchain and other bitcoin wallets really being the competitor to paypal) have only just kicked off in the last few years.
Of course, though, once the same amount of people KNOW about PayPal and Bitcoin, Bitcoin will obviously be the preferred "way to pay"
We can all see paypal trying to come together with bitcoin (basically the enemy surrendering before their defeat is publicly seen) by integrating it into braintree.