I looked up
Languages of the Philippines on Wikipedia. There're so many languages and dialects!
To answer your question I decided to use the table of the numbers of native speakers for each language (in the middle of the page) and take the top eight. So, my answer:
Tagalog, Cebuano, Ilokano, Hiligaynon, Waray-Waray, Kapampangan, Chavacano, Northern Bicol.