I wouldn't say I get obsessed with pokémon since that would be narrowing the world view on the franchise as a whole, but there are some pokémon that appeal to me more then others, and this changes at unpredicable times,
Currently, I really like Mawile, Misdreavus, Roselia and Kirlia. I really would like to snuggle with them if they were real and such.
Amazingly, im not obsessed with Pachirisu, just squirrels.
At the moment im obsessed with Lucario, Magmortar, and Gallade, Mostly because they look so awesome. I also have been obsessed w/ Scizor, Blaziken, Absol, and Mewtwo.
I am currently, and have been since it's unveiling, obsessed with Perap, I currently have four Perap plushies and a figurine, and a collection of Perap-based screenshots, fan-art and the like...
I really like Swampert. But I wouldn't say I'm obsessed with it. I am, however, a huge fan of FEEBAS. It needs more love, and it isn't all that ugly. If you look at it properly. It's rather cute! =D
Plus, unlike Magikarp, it can learn a few good TMs, such as Ice Beam. Feebas is a good Pokemon if you learn to look past how everyone stereotypes it. And not just catch it cause' it evolves into Milotic. D:
I have a box full of cute Feebas in my Emerald game, which I gladly trade to my many friends who vow to treat them with love and care. 8D