First time at a Disney park (Disneyland) and I only have one day. Is Park Hopper worth it?

I've never been to a Disney park before and I'm going to Disneyland with my wife in February. I know this has been asked a few times around here, but most first-timers are visiting for more than one day.

I've read about both DL and CA and I'm leaning towards DL, but I see people saying CA has more cool adult rides. However, I'm not discarding the idea of park hopping between both. We're both 30 with no kids, and I don't think we're coming back to SoCal any time soon. What would you suggest?

Edit: Thanks for all the great answers! PH + LL seems to be a great combo for a single day and will probably be my choice.