Chesterton Montessori has preschool 5 days a week from 8:30-11:30 and they offer after care (before and after) from 6am - 6pm (I think those are the times we don't use their after care we just go to class) I LOVE LOVE it! It is a 3-5 year olds working together. They have three morning classrooms. My son went this year and both my children will be attending next year. It is off Burdick Rd (behind SandCreek) I drive from Valpo (15 miles) and feel it is totally worth it! Their phone number is ###-###-####. They have school until May 27th so if you get a chance I would take a tour and see the children working...they have inside and outside "work" environments for all three classrooms. They have a completely open door policy. You can go in and observe anytime you like (as long as another parent isn't already using the observation room) Each room has a two way window and small space to sit and watch.
I have also heard VERY good things about Little Lamb in Valpo. I have several friends that have children there but I do not think it is 5 days. I have not heard good things about Littlest Angels, but don't have personal experience and again, don't think it is 5 day.
I know one of the Valpo Y preschool teachers and she is a really great person. I don't know anything about their program, but if I were still looking, it would be a place I check out just because I know one of the teachers.
Oh, and I know some moms who use Mirror Image (it is a dance school with preschool) those that I have talked to really like it, but I don't know anything more about their program. My daughter takes dance there and LOVE LOVES it!!
GOOD LUCK!!