I go to Gymboree in Herne Hill with my 16 month old and we both love it, we also used to go to Gymbabes at St Faiths but I found it a bit grubby / noisy / random / too crowded and I think he was a bit overwhelmed by it as he spent a lot of time just staring at other children instead of doing anything. (Mildly annoying when you are paying ?7 a time to be there!) Granted he's also quite a bit older now than he was when we went there but he absolutely loves Gymboree and I've been really impressed by how nice and clean it all is and how adventurous he is when we go. There is some free play and some group stuff including bubbles and parachute games and I think the balance is just right, with much more songs & interaction than gymbabes. It is expensive though and you have to sign up for I think three months, although it's then nice that you see the same people every week. And he always naps really well afterwards which is a bonus. I've also heard really good things about Whippersnappers and I'm going to try that soon too.