Many of our customers really like our Paypal DPM module as it allows direct payment on your site with Paypal. They don't have to go off site and it looks like a normal payment method even though the data is posted directly to paypal to process.
http://www.bcsengineering.com/store/paypal-dpm-for-x-cart.html
Let me know if you have questions!
thanks,
Carrie