Paintball Adventures, Shutdown Extreme Park, Rocky Mountain Paintball and High Plains Paintball. Paintball Adventures is cool. I've only played on the speedball fields there but they are well set up. I didn't really care for the rest of them.
The staff at APP are the best. The rec fields are a lot of fun. The speedball play there is awesome. The earlier assertion that safety is neglected is absolutely false. The APP staff is very safety concious and while the chrono is relatively close to the staging area it is monitored and faces into a safe area.