The World God Only Knows. If nothing else, it's worth watching the various seasons for the opening songs.
To Love Ru (very tough to find appropriate gifs from this series, especially with the level of fan service that came in with the Darkness seasons )
Yes, I know that it's not really "anime," kind of borderline at best since the original series wasn't made in Japan. Yet, it's always been something of a joint venture between the US and Japan, and the movie was animated by an Asian production company if I'm not mistaken, and Japan picked up where Marvel/Sunbow left off afterwards so in my book it gets a pass.
Yeah, gotta agree with that. The animation quality on a lot of that film rivals what you could see in anime at or around that time. The opening shot of Unicron as it passes the camera on its way to consume a planet is fantastic.