Good programs are different for everyone. We have tried a few and some were great and others not so much. There are Christian programs and secular programs, historical literature based, workbook based, computer programs, online programs. All of those factors will depend on what you need or like.
Personally we have tried Sonlight (love it), Math U See (really love it), Accelerated Christian Education (not so much), and Switched on Schoolhouse (alright but not for us). All are Christian but have very different formats. Sonlight is historical literature based, comes with lesson plans, and a TON of really great books. ACE is workbook based, my then 2nd grader found it too easy, boring, and would finish the entire months work in a day. SOS is computer based, it does most of the grading, sets up due dates, and all kinds of stuff. It was a great program challenging enough for my then 5th grader (same kid) she just didn't like being on the computer all day, a few lessons was fine but all day gave her headaches.
There are other programs like K12, Christian Lighthouse Academy, and Penn Foster to name a few. It all really depends on your preferences and who you are but one of the joys of home schooling is finding out who you really are.