Math Games

My 3rd graders have started learning multiplication. Already I am ready for them to memorize these facts, especially when I know division is around the corner! I have been trying to find new and good math sites for the students. There are tons out there, but I would like to use some that others have had success with. I would especially be interested in any that help students with multiplication or problem solving. Many of my students are getting internet access at home and some amazing sites might help encourage them to practice at home. So please, pass on any and all great math sites. Thanks.