cheque or direct deposit if you hold a European bank account. You have to send them an invoice the end of each month when they email you, and they mail out a cheque within the week.
If you are looking for an in-text ad provider that pays via PayPal, Kontera does. In fact, Kontera publishers can choose from check, direct wire or PayPal. Our payment terms are NET30 and are paid automatically (not requiring any invoicing). For more information: https://www.kontera.com/moreinfo.asp?type=1&BD=15