Sites are a labor of love. You could go the route that GameDev chose and offer advanced accounts that give you some feature(s) for a yearly cost.

Personally, I won't use PayPal so I can't say that I would donate of PP was the method. Seen too many people/companies screwed by PP in the past to be one of their supporters.

As for DG, cut a deal with the games your hosting and for a yearly fee (say $20) give the person 1 or 2 free full version(s) of a game listed on the site. Give part of that back to the developer, and pocket the rest for expenses. Logistically, this makes people feel better about themselves while still satisfying their greedy side. Of course, it also means you need to advertise some commercial games