The list is too long. I'll order the positive ones I know from best to the least:
1) Park House English School - Top rated by the Education council for years (better for English Mother tongue)
2) Sherborne School (better for English Mother tongue)
3) International School of Choueifat (better for Egyptians, Lebanese, Syrians & Palastenians)
4) Qatar International School (multi-cultural)
5) Newton British School
6) English Modern School (better for Qataris)

And here is the black list:
The Cambridge School
American Academy School
Al Maha English School (Good only for Qataris)

If you are keen to join an "Islamic" school Iqraa is a better choice