We're struggling with what to do with our dd next year, who will turn 5 shortly after school starts.
Option 1 is kindergarten in our local public school. It's a "fine" school -- well supported and attended by the community, active parent body, good test scores. Very traditional in instruction -- I observed a kindergarten class for about 30-45 minutes one morning, and the kids were sitting the entire time, mostly with the teacher "lecturing" and very little (but some) participation. Kids in kindergarten only go outside once a day (it's full day) and there is no music, or science (although the principal claims that all those things are done with the classroom teacher). They do go to art, although I can't remember how often. Large class sizes -- in K, one teacher with 22 kids, in upper grades one teacher with 25-26 kids. We live half a block away.
Option 2 is kindergarten or pre-k (our choice) at a private, progressive school. I just visited today, and it's everything I would want a kindergarten to be -- lots of time outside, lots of free choice, toys and blocks and dolls and art in the classroom, time spent in science, "creative movement," art, music. The rest of the school is also progressive, but I didn't focus as much on what that means in the upper grades (it goes through 8th). Small class sizes. The downsides: it's expensive (although we can handle it, with the help of willing grandparents, but there is likely little socioeconomic diversity) and it's 45 minutes away by school bus, so long commute to/from school and friends will likely live far away.
There are other private schools closer to home, but none are as good -- or as different from the public school -- as the school in option 2.