Paypal. Reasoning? Paypal is offered a lot rather than 2checkout, so chances are you will have to use paypal instead of 2checkout.
well .. paypal sometimes freezes your account with no explanation ... but still many people use paypal .. you want to play it safe .. go checkout .. want to risk a little and maybe reach more clients .. go paypal
Paypal is way better that 2checkout simply because more people use them, you will have a hard time searching for someone who will pay via 2checkout.
2co I think its better because they accept also PayPal when your clients want to pay and acepts some Cards that PayPal dont acept them.
If you are considering Credit Card payments then its really hard to compare 2checkout with Paypal, Paypal is quite lame for Credit card payments, they only accepts Credit Cards from the countries they support and they are not efficient enough in fighting against CC chargebacks.
Well, 2Checkout is better because not only that it accepts credit card payments, it also supports paypal payment. It also has better pre-transaction checks while Paypal merely relies on the verification process which seems to be easily foiled. 2Checkout does not require or prompt anyone to sign up with them and it can be a clean single transaction. It also supports almost all known countries.
2co is only good if your outside of Canada and the states. If you live in the states or canada you can get cheaper rates elsewhere.
My advice is to use both. Give your customers the option. Not everyone can use paypal, and not everyone will want to use 2checkout. 2checkout might also offer paypal payments, but you pay more in transaction fees.