Do you think that Ah! My Goddess is a unique series?
I think that it is, cause even though Keiichi is a loser type, doesnt have much luck with anything really, well before meeting Belldandy anyway. It isnt generic in the sense that the guy/girl is going after the object of their affection. Its a good romantic comedy series, with alot of events going on through out the manga and ususally only carry for a few chapters maybe a full volume, which makes for alot of material but seeing that 3 of the main characters well 4 later on with Peorth, are Goddesses and then all the Heaven/Yggdrasil related stuff and so forth, you dont seem too much of it.
But the relationship between Kei and Bell is different cause they have similar feelings, although it may seem a little kindergarteny at times ^__^;; and with Urd wanting them to get together and Skuld pretty much being the opposite, makes for good reading/watching :D