My current list was made due to their association with another work; I've tried watching the Fate/Stay Night anime twice, but ended up dropping it both times, with me finally resorting to summaries of the VN. Fate/Zero was an amazing watch, and Carnival Phantasm was hilarious. It only seemed right that I give the VN some proper time. It's kinda the same deal for Tsukihime; Carnival Phantasm and Melty Blood piqued my interest.
I've been enjoying the Total Eclipse anime for the most part, and since I really love the universe (I like giant robots, and I like airplanes, so naming the giant robots after real airplanes seemed like they were explicitly marketing to me), I'd like to learn anything I can about it. After absorbing everything I found interesting at the Wiki, playing MLU and MLA seemed like the best step to take right now.
As for an actual answer to your question, I don't really have one; I guess I'm up for anything, really.
I like the Clannad anime, but heard the VN was a huge timesink (even by VN standards), and I already have a lot of those at the moment. I'll put those two in my backlog though.