I have tried a lot of ice cream and frozen yogurt and have admittedly become somewhat of an ice cream snob. The following is my top list of companies.

1. Kawartha Dairies
2. Häagen-Dazs Reserve
3. Ashby's Sterling
4. TCBY (I've had some nasty TCBY from improperly cleaned and managed soft serve machines)
5. Dove
6. Cold Stone Creamery
7. Ben & Jerry's
8. Blue Bell Creamery
9. Publix
10. Baskin-Robbins

Worst I've ever had:

1. Carvel
2. PET
3. Mayfield
4. Nestle (tasted like styrofoam)

Other:
Dibs
Full Circle
Lowes Foods
Breyers
Blue Bunny
Harris Teeter
Braums
Marble Slab
Dairy Queen