Course Cell saga was really good too, I enjoyed it as much as Frieza saga. Buu saga too but then you'd start looking around and feeling bad for Tien, Krillen, Piccolo, Chiaotzu, and eventually Gohan and Android 18 where they are just there to fill spots.
It's why when it comes to DB-DBZ, I enjoyed DB all the way to the Frieza saga because everything felt like some adventure where it just leaves you in suspense on what happens next.