JP Morgan Chase. They aren't sexy. They don't have a great API. They don't have a good UI. They're slow as shit to process your paperwork. Our rep calls us every time even though I have asked him to email instead. They suck in almost every single way you can imagine. But, they also tend to function like a real bank, and outside the last few months, have treated us pretty well.
I've had this same experience with Chase on my business accounts. They're boring but attentive on the customer service side.