Okay this one is too hard, there's too many I love, so I'll do a top 12 in no order.

1. The Bake Sale (OG, not the remake)
2. The School bus
3. The Funeral
4. The Test
5. Black Yoshi's Scam
6. Chef PeePee the Babysitter
7. Junior goes to the Moon
8. That Cookie Crisps video
9. Jeffy's Grandparents
10. Jeffy's Homework
11. Uh Oh, Spaghetti-Os
12. Goodman's Son Gets a Job

I also love the Playtime series and Chef PeePee Quits