Hi,
I would choose the program that you like personally, based on the instruction, professors, and the areas of research you want to pursue. If you are looking at Riverside as your option based on the fact it is in California (weather, for example), keep in mind that Riverside tends to be very hot during the summer and you will need to stay in air-conditioned spaces to stay comfortable.
Btw, congratulations on your acceptances. I am also a comparative literature grad.