My DS is currently with Tien Hsia Language School, but he doesn't really like it. I found out about 乐学堂 through Geylang East Library, and went to talk to one of their staff today. It seems pretty impressive.
They are affiliated to Iknow Pte Ltd and Besta (the Chinese Electronic dictionary). For preschoolers, the lessons are based on story telling. For primary students, the first 1 hr of the class is MOE syllabus based, the latter 0.5hr is interactive/fun activities e.g. Chinese Karaoke/short films/internet/or newspaper reading etc. On top of that they have extra story telling sessions once a month, plus an phone set thingy you bring home, so the child can call the teacher when he/she has queries. Class size is small about 6-8 students. Supposedly the teacher will also call once a week to check on the child's progress. But I'm wary 'cos there's only 1 branch currently and it was setup a year ago. Anyone with feedback?