Yea I really really liked Blue Exorcist.. good characters and story.
Agreed. It's a shame the anime took a different route and then ended prematurely. Supposedly, they're not
too far off track, though, and could potentially come back to the canon storyline at some point. ...But I doubt they will. Sigh.
Pretty much anything from FUNimation is available on Hulu, Plus or not. (And to the best of my knowledge, Plus doesn't upgrade them to HD, like it would with other shows. Unless they've since changed that.) FUNi has a bunch of stuff on Netflix as well, although I've noticed a lot more titles from Sentai Filmworks and Aniplex of America showing up on there these days. Knights of Sidonia is actually listed as a Netflix Original, so I'm curious to see if they license any other anime series in the future.
...And on the note of Netflix: Fate/Zero. (Also on Hulu.) If you haven't already seen it, check it.
And on the Hulu end: Baccano!, Steins;Gate
Something recent, which was an amazing series IMO, and I see is available on Hulu, is
Nagi no Asukara. Maybe not for everyone, but if you enjoy some slice-of-life, romance, drama, etc., then I can't recommend this one enough.