Which one has a better program and better opportunities?
Assuming both are affordable, is there a preference for the campus life between the two?
Both schools are ABET accredited so their courses and programs will be similar. Have you done a side by side course comparison to see if there is an advantage or particular emphasis in an area of interest between the schools?
My younger son is a current CS major at SDSU and did consider UCR 4 years ago. Both CS curriculums were similar, financial costs similar due to a UCR Chancellor scholarship, but the SD area and the social vibe of SDSU won him over.
The SDSU alumni network is very strong so there are many good opportunities available. I cannot speak for UCR, but I am sure with the UC Brand name, the Riverside area could have similar opportunities. Remember, no one is going to hand you an internship or job, you will still need to seek out on your own at either school.
Pick the best fit for you, academically/socially and financially.
Best of luck with your decision.
You may want to ask the SDSU CS department for assurance that it will not change requirements without enough advance notice in a way that causes students part way through the old requirements to be delayed in progress or graduation, as may be the case with the SDSU EE department, as described in this thread:
http://talk.collegeconfidential.com/college-life/2074999-my-school-made-horrible-changes.html