I'd like to address the negativity being thrown out there about Mikasa's devotion to Eren that some are twisting to make Eren look like some kind of victim. To understand Mikasa you have to know where she's coming from.
This is the first time she met Eren. I didn't post the long backstory but to put it simply just before that Mikasa had watched both her parents get slaughtered by a bunch of thugs. Those same thugs were going to "traffic" her. She had given up. Her cheerful, carefree life had been cruelly snatched from her. She was "cold". Then out of nowhere this boy she's never met shows up. He didn't just save her. He urged her to live. Afterwards:
Having no family and nowhere to go, that same boy and his family took her in. He wrapped that scarf around her and made her "warm". That scarf is a symbol of how much it all meant to her that day, she's kept it for years and it has been her lifeline. It's easy to dismiss her feelings for him just to make a point, but those feelings are deep rooted in gratitude, admiration, hope, salvation.
It takes a strong woman to love a broken man. And that's exactly what Eren is. Sadly he suffered the same fate as Mikasa did and watched his own mother die gruesomely in front of him. It drove him almost insane. He's not always kind to Mikasa, sometimes he takes her for granted. Yet Mikasa has never given up on him, never abandoned him. She understands him more than anyone else in the world and that's why he confides in her. No matter how crazy his thoughts are or how irrational he is he knows he can tell her anything, even if he knows she won't agree. That's the level of trust between them.
But I find it amazing that despite what they've been through, how much they suffered, Mikasa still looks ahead. She wants to save everyone, yes everyone, she wants to defeat the Titans. She wants to live a peaceful life with the ones she cares about. She wants to go exploring the outside world with Eren and Armin. She has dreams just like any other girl and she's working to achieve it. But those dreams involve Eren so yes she comes off as too intense at times but she has her reasons, and like we saw before, Eren doesn't seem to mind as much as some of you make it sound.
Mikasa is strong when the situation calls for it but she has a kind soul. She's loyal even if someone doesn't always deserve it. She takes your dreams and does everything in her power to help you fulfill them. She takes care of you when you forget to take care of yourself. All Mikasa wants is for the person she loves to be happy and that in turn would make her happy. Its not about being dependent, it's about loving someone to the point where you share a bond so deep it's almost like you're the same person. Soul mates some would call it. It's a long road ahead but never once has she faltered and knowing Mikasa she never will. So do I think she would make a good waifu? Absolutely! With someone like that by your side it's impossible to feel like you couldn't do anything. In fact it's the opposite. You'd feel like you could do everything