Just got back from The London Aquarium (?9.50/adult, nearly no queing) - it's really good. Some excellent stuff in there (the sharks getting an unfair amount of attention ;-) I suspect Finding Nemo did quite a lot for attendence numbers. However, if your kids are unknown to me, I may want to kill them (all the non-English kids were far better behaved mind you, and would be largely exempt from my culling).
<--break-->