The Chinese Lantern festival is going on now, and while they look cool during the day, night time is when they will shine (get it?). The annual membership is a great deal if you come more than a few times - we have a 3 year old and he loves the water tunnel. He gets soaking wet but it's definitely worth it to see just how happy he is.
The grounds are amazingly beautiful, and you can walk around for a few hours, bring a picnic lunch, and really just sit and enjoy the weather.
A better wine bar would be nice - but we really just go to be outdoors, and it's one of the few things I don't think alcohol would make better!