Until what age did you put your baby in a crib/ playpen (whether to sleep or to play)?

My babies slept with us on our bed. I am a firm believer of co-sleeping. Also it made it easier for me to check on my son in the middle of the night, without having to walk to the crib, and I was also about SIDS (sudden infant death syndrome). To play, yes we used the playpen till 6 months. We preferred him out of it, and used it more for when we needed to take a quick trip to the loo!