I have done the lot over the past 28 years, from simple family celebrations to go-karting, paintballing to picnics. Party bags can be as simple or expensive as you want - and years ago I did find some watches in a pound shop so popped them in. Pound shops were always my hunting ground for party bags.
The children enjoyed them all equally, I think. The biggest difference was in how much pleasure I got out of them. I was far happier taking them all to a venue where I knew my dogs, cats, house and garden would all be safe and undisturbed, and I would not be faced with stains, spills, exhaustion and washing-up until late into the evening.
This year we were shocked by my son's 18th birthday request. He wanted a day's shopping and lunch in Cambridge, followed by a meal in his favourite restaurant, with a cheap meal for a few friends in the local chinese buffet restaurant one night during the week. We had thought he would want a huge party somewhere, ie marquee in our garden, and were rather dreading it.