The first we signed up for was a localish soft play centre in Eastleigh called Gambados, which opened in 2007. Unlike a lot of other play areas we've visited, the mini one never gets bored here as there's lots of age appropriate stuff for her to do.
There's two main play areas: the first caters for under 4's and features it's own slide, sensory area and ball pool, plus a small toddler area which is very padded so great for little ones learning to walk. The second is for the older kids but the mini one has been climbing up it's 3 floors since she was about 2.5 and squealing with joy down the big wavy slide! There's also a teacup ride (unlimited rides are included in your admission) and a climbing wall.
There's lots of seating for adults and a handy little cafe that does limited hot food (nachos are yum), sandwiches, cakes and kids meal boxes. It can be very busy and we have left early before when we've failed to find anywhere to sit or just felt it getting too cramped, but early Saturday morning and weekdays (term time) are all pretty safe bets. They do offer parties so you can sometimes notice the place get busy then suddenly quieter again as whole groups go. There's a dedicated seating area for parents involved in the parties.
It can get pretty pricey if you have a couple of kids, but as season pass holders now, I pay less than £10 a month for unlimited entry for the mini one plus two adults plus we get discount in the cafe and off parties.
It's also really secure. You check in and check out so the kids can't leave without you, however I have noticed this be a bit slack lately with staff just buzzing people out without checking cards/child/adult etc. People can't get in without being with a child which makes it feel safer.
Negatives - the noise. This is not a place for anyone with a sore head and feeling a tad fragile! But time it right when a friend is also their with their kids and you can sit back, eat cake and catch up while the kids are happy.
If you want to find out more about Gambados, please visit www.gambado.com
Disclaimer: I received no payment or incentive for this post, we are annual pass holders but pay ourselves.