I've always loved Theon & Jorah, but I'm going this with Jon right now. He's always been kinda ehh but I'm working my way through the series again and I'm kinda loving him this time. =D

@DarkSarcasm I had the same experience with Jon. At first I thought he's plain but later I could see his character more clearly after he was made the commander.

Theon has really grown on me through the seasons.
Jorah is my favourite hands down and by far since day one!
With Margaery was hate at first sight (her death was so satisfying) and as for Jon...well it's the way backwards for me! I mean I used to like him (a lot especially during season 1) but as the series progressed I kinda felt detached to the point that he appears in a scene and I yawn. Now I really don't care.

@LLheart I liked Jorah since the first episode but started liking him more as we knew more details about his character.
Yeah lot of people feel that way about Jon xD

To me, Jon actually felt like a protagonist from the start. But, Jorah seemed like a side character whose role is simply to support and act as a loyal servant. Later, he exhibited more depth.