Hi, i've just gone through the admission process in a kindergarten for my son in Tseung Kwan O so I can share a bit about this.
The first one you may want to consider is Abacus kindergarten in Clearwater Bay which is affiliated with ESF. The advantage of this kindergarten was that kids here got priority to the ESF school in Clearwater Bay. However, this arrangement will change after this year, my understanding is that there is still some sort of priority but not as high as before. It is a play-based approach and all the teachers have an education certificate and almost all are Caucasian.
I ended up dropping this option when it became clear my child wouldn't get a morning slot. This kindy is also starting a bilingual class, which may interest you.
Further along in Sai Kung, there's Woodlands, but it's actually quite a long ride from TKO. There's also Garden House in Clearwater Bay that follows the Waldorf method. I've heard good reports of this one.
Newly opened in Yau Tong is Mills International. I went to their open day and they seem very "international" but they took care to stress that they understand its a competitive world and so they would ensure that students were learning and not just playing.
Which did I pick for my son?
I chose Deborah International in Tseung Kwan O because I'd heard decent reports from the mums in the playground who send their kids there. I'll admit that the Western teachers there don't seem as experienced as the ones in Abacus and Mills. However, I went by the word of mouth reports which were positive. It's one of the most reasonably priced schools and has been around in TKO for a long time. Plus, my son did extremely badly at the interview (he was just over 2 years old then) and they accepted him, which I took as a good sign that they actually understand kids a bit.
I live in Tiu Keng Leng and there's a kindy called Box Hill there. I've been to a couple of their open days, the teachers seem okay, though I've heard some negative reports about staff changes. However, the kids in my estate that go there seem to be okay.
Another one I applied to was Learning Habitat in Lohas Park. I was interested in their Canto-English programme. However, since my son got into Deborah first dropped it.
There's also Greenfield and Greenville mentioned above that seem popular.
So lots of options you can see. I don't have first-hand experience on their quality as my son will start kindergarten in August.