I kind of liked Zhivago the novel (not a big fan of long novels, and I slightly prefer the movie to the book), but Pasternak is definitely a better poet than novelist.

If you want a great work of literature about the Soviet experience, check out Anna Akhmatova's "Requiem." (also one of the greatest religious poems of all time.) There are a number of great Soviet-era novels (in addition to Margarita), but Zhivago would be near the bottom of the bunch.