It depends what genre you like, from your previous anime i would guess that you enjoy Action/Supernatural anime so i would recommend:
Steins;Gate - MyAnimeList.net
(This anime is coming top 10 with Anime News Network and myanimelist)
Angel Beats! - MyAnimeList.net!
(Its from the creators of Clannad and has a good rating in ANN and myanimelist)
Fullmetal Alchemist: Brotherhood
Fullmetal Alchemist: Brotherhood - MyAnimeList.net
(It is much better than the orgiinal as it follows the manga and the original cuts off half way from the manga, and it has a deeper plot and ending, with a mix of new characters)