Many schools and teachers post a list of recommended websites for learning games for their students. Here's a curated list of educational and engaging learning games for schools to post on their website and send out to teachers. Obviously, it can be adjusted by the teacher's or school's focus and their types of students.
Syllables and Segmenting Games
Writing Lessons and Activities
Brain Training Games
Symbaloo's Visual Bookmarking has some great webmixes!