I was in a similar place, once. I attended a Northern California community college and transferred to UCLA (Biochemistry); I was accepted at UCSD, and UCD (and UCI, I think). I didn't apply to Cal because I didn't want to go there, but not because of its academic rigor. Most of my friends went to Davis. I go to Davis, now, but I'm doing an MS in Pharmacology and Toxicology having earned my BS from UCLA last year. Currently, I tutor and provide transfer guidance at 2 different Northern California community colleges. I will also be starting as a mentor for new transfers and non-trads at UCD, soon.
Okay, before I give you my sage advice, just know this: a lot of your friends WILL wash out no matter what school they go to. Some of mine did. Just from my transfer friends, one went to UCSB for Physics and earned a 3.2 (this guy was pretty smart); another went to UCD for Chemical Engineering and got a 3.0 (semi-smart). Then, there's another that went to UCSC and earned a really high GPA in Biochemistry and is now at UCLA doing a PhD in Chemistry (and struggling, from what I heard); there is also the guy that went to UCSD for Cell/Molecular Bio and did pretty well and is now at U of W doing a Microbio PhD (this guy is pretty smart and would have done well no matter where he went). Other people I knew went to Davis and did easy majors like Human Development and are now taking prereqs for dental school at the city college; most of the rest that went to Davis never really went too much farther in their educations, and now work in sales and/or Bay Area tech startups doing email jockeying, or are in nursing school. I don't think that some of this crowd were too bright to begin with. As far as I know, from my 20 or so transfer friends I'm the only one that will be going to medical school.
With that out of the way, I transferred to UCLA; trying to work at the same time (and having a relationship), I earned a 3.2 my first year. I didn't know how much I had to study to get good grades, basically. When I figured out how to devote TIME to my school work, I did okay and earned a 3.5 Junior year, and a 3.75 Senior year. I have a 3.75 in all my upper division classes. I worked my ass off to get these grades. My Cumulative GPA is a 3.5. No matter what you do, learn from this and start studying your ass off as soon as you get to the UC, especially if its one of the big ones in a science.
I would still have gone to UCLA (or Cal) if I had it to do over again. If you applied to UCLA, I'd consider it. If not, no big deal. But, I wanted to challenge myself, and I knew that if I couldn't make it there, that I should do something else with myself. That's just me, though. I believe that people who take the easy road don't get far in life. I'm not saying that Davis is easy, but I wanted a challenge, and to get out of Northern California. You've got to be willing to gamble on yourself, though, and understand that the adjustment period may hit your GPA like it did mine if you're bogged down in a life outside of school. I transferred in without a lot of courses in my major, so this was kind of a buffer, too. I'm not saying don't go to Davis, but if you're doing a soft science or liberal arts at Davis, well, I'll just leave it at that.
Don't take this the wrong way, but from what I've seen at Davis over the last 6 months, I'm disappointed. They've watered down their Chemistry courses, put disclaimers onto their math courses "intended for biology students who do not wish to take more rigorous Mathematics courses..." (
http://catalog.ucdavis.edu/programs/MAT/MATcourses.html) and its known that people coming here are only coming here for grade inflation. This isn't a reflection of the school, itself, it's a reflection of an easy transfer agreement policy with community colleges, and an exodus of Cal rejects from the Bay Area (like you). And UCD is still a top ranked school, nationally.
But, I would be lying if I said that this place isn't filled with people that either ran from the harder UCs or didn't get into them in the first place. No one really comes here other than to be close to home, or for one of the above reasons, because we know that it isn't the scenery. Everyone here is from Pinole, Santa Clara, Roseville, San Jose, Mill Valley and places like that, and everyone here has the story about "getting in with the TAG but being on the fence about going to Cal, UCLA, or UCSD" that transferred. Hate on me all you want, but I'm a current UCD student and will call it how I see it, especially after coming from a premedical Ivory Tower like UCLA.
This shouldn't be a surprise to you, since an easier GPA is why you're considering this school in the first place. There are just too many easy majors, and not enough rigor in the sciences at Davis. Other than that, the PC climate here is a bit much. I lived in Davis something like 6 years ago, and this town has seemingly become more isolationist and PC, if such a thing were possible, since then. I've always liked Davis, though, especially as a cyclist. I live in Sacramento, now, though.
Long story short, you may become a DO if you go to Cal (or UCLA); if you go to Davis, you may earn a 3.9 in Human Development, and never really learn anything during the time you're there. Is that really worth it, though? Only you will know the answer to this question. If you do go to a big UC and do well in a hard science (Chemistry, Biochemistry maybe, Physics, Math, something like that), the world will open up to you, however. As a community college transfer, you're already facing discrimination whether you're aware of it, or not. You've got to do something "extra" to get ahead no matter which path you take.
I'm starting at UCD in a position to mentor new transfer students and other undergrads, soon; you may want to look me up if you come here. Hope this helps. Oh, and don't go to a CSU.