Have you ever watched an anime you thought you would hate but ended up liking/loving?

Yup, Naruto :)
Thought it looked so stupid by just surface value. But after watching it and knowing all of the characters personalities/back-stories/jutsus, I just absolutely fell in love with the series.

Naruto has a perfect balance of everything to create this amazing fantasy world to escape to unlike any other show for me.

there are two

1. bokura ga ita , at first i didn't like the art but it changed by the time or maybe i just got used to it

2. tokyo ghoul , i thought its just a silly violent anime in the first episode but it ended one of the best anime i watched in my life

mirai nikki and kokoro connect are a few

Definitely Shingeki no Kyojin / Attack on Titan. I don't know, when I heard the word 'titan' I though of some silly robot action sequence and automatically assumed I would dislike. But after giving it a try I discovered it was actually quite enjoyable, not to mention the manga is a masterpiece.

I really thought that I would hate Durarara!! I kept seeing pictures and I thought it would be a mecha anime for some reason (I guess Celty's motorcycle?). But I was sssoooo wrong! It wasn't anything I thought it would be and I loved the ending how all the stories twisted together.

Also Daily Lives of High School Boys. The title sounded lame and I thought it was going to be boring..... HA.HA.HA. Far. From. It. I freaking love this anime now, i've seen it 3 times in the past year! I can't get enough of it, it's still funny every time I see it.

I can only think of this.

hmm Darker than black i guess. i watched the first bit of the first episode a while ago and got bored and thought that it would just kinda be boring the whole way through. then my friend got me to watch and it's in my top 10 and has my fave male anime character! ^_^

Natsume Yuujinchou

Code Geass

Hmm, most likely..Yeah, kinda weird but Fullmetal Alchemist. A kid with metal limbs and a brother in a suit didn't sound very appealing to me. Though after I watched Episode 1 I was hooked and Ed is now one of my favorite characters, along with Alphonse and Roy. One FMA character I dislike is Winry. She dresses far to skimpy (she's a freaking mechanic, she should be wearing COVERING clothes) and was about to undress in front of Ed once. Yeah no. Probably the hugest reason I dislike EdWin.