great idea for a thread!
I can add:
Surrey - Bocketts Farm:
Bocketts Farm Park
Surrey - British Wildlife Centre:
British Wildlife Centre, Surrey. More than forty different British wild animals in large attractive enclosures.
Surrey - Chessington World of Adventures (offer fab midweek deals for under 5s):
Chessington World of Adventures: Official Website
Dorset - Sea Life Centre in Weymouth, the best one we've been to:
*Official* SEA LIFE Weymouth
Kent/East Sussex border - Bedgebury has an award-winning play trail:
http://www.bedgeburypinetum.org.uk/