I offer paypal and 2CO and I would say 90% use paypal, I prefer 2CO because they have an extensive fraud check, heck they were even denying me in the beginning until I called them and had them put in my file that I have a European IP but an American address. They thought it bad business that I could be a customer being rejected but that I could also be a business owner using their services. I thought it was funny and didn't mind as it just shows they take the fraud checks seriously.
I would love to get a merchant account some day but for now I prefer this, less work for me. I still call and verify but at least most of the rest is done.