As it's been said before, Zettai Kareshi, or Absolute Boyfriend, is a tale of the main character falling in love with an android. Though it may seem strange, as you continue to read, you grow to love the characters as they are all original and unique in their own way. (I, personally, am in love with Soshi).
Fantastic art (Yuu Watase is the author of Fushigi Yugi and "Ceres") and amazing choice of panels and story layout - though some bits grow very far-fetched - as it includes humorous and beautifully crafted scenes for all to see!
Perfect ending, in my opinion. The story, overall, makes the reader emotional and utterly interested, pleasing the eyes with pleasurable pictures (for girls at least... though you catch a few naked women at times) so it really is almost perfect.
The only downside is that is that I find the character, Night, very... off-putting. That's all.