By USD I think you mean San Diego, not Davis?
As between USD at close to sticker price and Chapman for free, I'd take Chapman in a heartbeat. Frankly, neither school can justify the obscene tuition they charge, so I'd go for the cheapest option. Your job prospects graduating from either school will be very similar, with an advantage to USD if you want to live in SD. I don't think many employers draw a big distinction between these schools, they operate on a fairly similar level.
I'm surprised that if you had the numbers to get a full ride from Chapman, that you did not get a better offer from USD. Their admissions numbers are not too disparate.
Last note: be prepared to live and work in Southern California. I don't know where you are from, but these are not exactly the kinds of schools that will land you job interviews in NYC (or at big firms) based on pedigree. Not really a big deal, but something to be aware of.