I liked Angry Birds at first when it was released on iOS, got bored of it and tried to get back into it and I hated it after that.
Since the release of Angry Birds Space though, I have started enjoying it again. Space has a little twist in it, bit the same concept as to defeating those green little piggies! Also I like the how the Birds looks now along with some of their new abilities, which is only the yellow bird (now its purple) who really has a new ability, the others are no different except their cosmetics.
If you were to play Angry Birds, I would suggest to just get Angry Birds Space and Angry Birds Seasons (for the old original feel of angry birds, but it is supported highly due to new stages coming out for every holiday)