Levi, Jean, and Annie.
Levi for breaking the "cold guy with a heart of gold" stereotype with style, and for never loosing his cool even at the most demanding situations. Very inspiring for me
Jean for being the character that we can relate to, and for most growth.
Annie because she's a really intriguing character. Have to be honest that Kitten's early fanboying posts were my cause of my conversion to Annie-ism.
I actually started really liking Eren thanks to Anime ep 24 (which I love), but I think you're not there yet Eren! Keep working on it! (didn't vote for him)