That was pretty much totally amazing and brilliant and SO MUCH LOVE. JUST YES, YES, YES. The silliness! The exaggeration! The Christieisms! Fenella Woolgar who is always wonderful, but was even more so in this. When Christie slapped The Doctor down for finding sport in murder? SO GREAT. The stock characters who came straight out of Christie novels were perfect & A++ for the gay lovers. Erm... what else? Everything!
The whole Agatha not thinking her writing is Great Literature was really oddly poignant in a very cracky episode, but, I loved it. Especially since, you know; massive fan. "Solving the mystery" = genius.
I kind of love Donna. It's taken me a while, I'll admit, but she really is AWESOME. And... in typical fashion, I might even lean towards Doctor/Donna far more than I ever did Doctor/Rose or Doctor/Martha. It's my friendship kink coming into play again. I just get the sense that they're happily comfortable together and have this great mutual respect and affection thing going on.
That was probably my favourite Doctor Who episode since Nine, although, to be fair, I always do love the ones where the Doctor and his companion meet Famous Writers, because they're always full of referential beauty (and reverential random ridiculousness.)