Lot of good sequels this season, I'll just highlight a few of the new ones that I find interesting.
Dansai Bunri no Crime Edge - I don't know how to describe this one, it's interesting so I'll leave it at that

DEVIL SURVIVOR 2 - Might have heard about this one if you'd played the games, this is an anime adaptation of the second game. There's a manga adaptation of the first game. Don't need to have played the games to understand what's going on.
Hataraku Maou-sama! - Hero and evil demon lord battling it out at the start, demon lord is forced to retreat and you know where this one is going to go before the next scene... that's right, demon lord and his general demon find themselves in our world looking very normal with barely any of their old powers. Turns into a great comedy show but wait, there's more! At the end of ep2 the plot is pushed forward so it's more than just a demon lord adjusting to our life.
Karneval - Judging by the art style I'd say this is a shoujo-anime and even the start seems very shounen-ai but turns into an interesting fantasy adventure that's a great watch. It's also one of those anime that has two famous seiyuu "teaming up" so people are making a fuss over it

Majestic Prince - Good to see the Gundam SEED art style back and also CG mecha

Photokano - High school harem comedy anime about a boy who just got his dad's old camera and took up photography, now there's actually a reason for dodgy camera angles

Red Data Girl - Looks interesting, 'nough said

Suisei no Gargantia - The second mecha anime you should be watching this season. There's a massive battle between mankind and an alien race and this one dude gets in a scuffle trying to do a space jump and ends up being hurtled back to Earth. At this point his humanity thinks the Earth died out due to an ice age and the location of it is currently unknown but some humans somehow managed to survive the ice age and now their technology is much closer to 20th century technology and they're unaware of life outside of earth.
There's probably a few more I could mention, honestly it's a pretty good season so my rule of thumb is to give everything a try (unless it's a sequel that you haven't seen the previous series) and see what you like
