Animes that deserves a season 2

Trinity Blood. Hands down. It's the series that I've always thought deserved a second season, but it can't be helped. Suano Yoshida-san, the creator of the series died from a lung blockage before the first season could reach its ending in Japan. I guess it would have gone on to have a second season if anyone had known the direction that Yoshida-san had wanted to take the series in.

I was going to say The Devil is a Part-timer, but someone already did... So I gave it a heart. As for Battle Programmer Shirase I would love to see a season 2 in the modern world with modern technology and programming. It is a great series that seemed to end abruptly without any plans to continue in any form. If I'm wrong then please direct me to more... :(