App site with reliable ratings + comments?
We'll reliable is somewhat subjective. But I can recommend App Brain (Play Store App) and App Aware (Play Store App).

App Brain provides some additional features compared to the Play Store and App Aware allows you to follow app streams based on a topic (games, sw development, etc.). Both try to suggest you apps based on the apps that you have installed. And both are not a new app market, they just redirect you to the Play Store if you want to install a app.