Planetes truly is an amazing anime. Definitely a surprise for me, too, as I also was just looking for something to entertain me for a little while, but recieved something much more.

The anime that surprised me most, though, would be Hunter x Hunter. Normally I despise those types of anime: weak protagonist with a lot of potential goes through numerous trials and becomes strong, but this one seemed to just...grab hold of your heart and never let go. I couldn't stop watching, and eventually I ran out of episodes to watch. It didn't cater to the popular demand of shallow action mixed with romance, like Naruto and Bleach, which made you feel almost connected with the characters.

Also, Hisoka is just pure awesome. Just love his sadistic nature and witty humour.