Sorry that should read Been here 12 years.
Can write longer reply now
If you're working in the city, there are reasonable communtes from Bangsar, Taman Seputeh, Mont Kiara, Ampang.
Longer commute, further out so a lot more house for your money - Desa park city, Valencia, Sierramas.
Assuming you want UK curriculum, the above schools are the big four.
IB/US curriculum at ISKL, Mont Kiara international (MKIS)
There is the ABWM (Assosciation of British Women in Malaysia) - quite traditional expat women IME, but I've not been a member for a good few years so will stand corrected. If you have pre-schoolers, look at IBU Family Resource group.
My kids are at Alice Smith, but I have friends at the other three UK curriculum schools. IME as follows:
British school: most expensive and still new, Fantastic campus. Secondary school largely untested. It's in Bandar Utama which is not a particularly expat area, and a good way out of town.
Garden International (second most expensive) - very large school on one site - nursery to 6th form, very built up area, traffic a nightmare. Owned by Taylors group which own several schools in Malaysia and Singapore. Strong academic reputation.
Alice Smith (third most expensive) - not for profit trust , established 1946, so the oldest in KL. Two campuses, so feels smaller than GIS. Primary Campus is in Bukit Petaling which is quite green, secondary is in Seri Kemabangan, a good way out of town. Good parent community. Most "British" of the UK schools- approx 35% UK/Irish.
Desa Park City School (ISP) - cheapest of the four- but there is not a lot in it really. Still new, but a good parent community. Very "international"- bigger mix of nationalities than Alice Smith.