Spent a whole day here and could have spent many more. It's not cheap and there's a lot to see so I would start early in the day. The crown jewels are just incredible and everything is displayed so well.
It's touristy - but its actually really cool. I just took my nephew after not having been there for a decade or more. Sorta spendy, but the restaurant up top has done a full 180 and is actually quite good.
agreed with peter. don't take this zoo for granted. it craps on our LA zoo, no joke. don't sleep on this if you haven't been. pay for the sky ride/bus tour, it's worth it -- see animals while you hop from one side of the park to the next.