Top Marks - good for maths
Purple Mash - ask your class teacher for your log-in, there are lots of activities/games across the whole curriculum on here.
Epic Phonics - we use a lot of phonics songs from here, particuarly good for the Tricky Words!
ICT Games - good for maths
Be wary of some phonics games, some of the games have an American accent in which the sounds are said differently to how we teach them.