Still a (somewhat disillusioned) witness , so writing with a slightly different perspective to most posters - sorry if it is still a bit too positive for most tastes!
Conventions - hundreds of friends - thousands of people milling around - nobody swearing or smoking - no litter. Gorgeous sisters (when I was younger). A good meal & a couple of drinks in the evening , just catching up with the gossip.)
Assemblies - delivering a talk in front of over a thousand people - (the best - when Chairman - just standing & listening as a great choir of singing voices washes over you)
Meetings - listening to (the few) quality speakers expound on the scriptures , sometimes dismissing the "script"
Construction - working with a great bunch of lads from all trades , the hospitality and kindness shown by the brothers. The satisfaction when the job is done.
Studies - seeing people make genuine changes in their lives , kicking destructive drug & drink habits and learning about the bible (albeit through a WTS vehicle)
Friends - going anywhere in the world and finding a united happy group of associates.
Family - a lovely wife & kids whom I would never have met outwith the "truth". The security that comes from knowing that the relationship is based on shared values and experiences.
Curiously , despite all the errors and a flawed doctrinal and organisational base , JWs have developed a network and structure that has given security , hope and a deeply satisfying way of life to millions of people.