I've found a really great workbook series: Funny Phonics and Silly Spelling
I bought the 6-7 year workbook for my older, but found that it was a bit too easy for her, so I tried it on my 5-year-old and she's loving it. Each subject is 2 pages long. After the 2 pages are completed, she gets to put a gold star (included) on the certificate at the back. She's really excited to get stars. The other day she said with excitement, "I'm learning how to read!". I thought that was great. And she really is learning how to read little by little.
I've ordered her a math workbook and my older 2 other workbooks and they can't wait to get them.
What workbooks have you all tried?