Familypark, Austria. The whole idea of going to this park was for +3 and nothing else, but I actually fell in love with the park. Rattenmuhle is by far and away the best family coaster I've ever ridden, it's also beautifully themed. The Mack YoungSTAR coaster is also fab, and again beautifully themed. The park is well kept, it's got a great selection of rides for all ages, the food is excellent, and so much more. It's really a park you need to visit to fully appreciate.
Drayton Manor Park. It's a park that gets a lot of hate but I thoroughly enjoy it. It's got a good selection of rides for children/teenagers and adults alike. The food and general cleanliness lets the park down, but apart from that I think it's a great little park.
Pleasure Beach, Blackpool. Easily the best park in the UK for so many reasons, the ride selection, the food, the cleanliness and the atmosphere. Such a great park.
Other notable mentions...
Brean, PowerPark (Finland), Pleasurewood Hills and Flamingo Land.