Now that it is December 2012 I am hoping it isn't too soon to start a thread that might be active to at least Christmas, getting us closer to spring 2013 regarding the best performing perennials which were new to your garden and so planted in 2012..
I will start:
SOLAR ECLIPSE heucherella;
I am not a big fan of heuchera and the like but the colours this SE were to me quite striking, quite unique
PRAIRIE GLOW: triloba
I have always liked the 'traditional' triloba but this bi-colour flowered plant was so cool. (I just wonder what the flower will be for the offspring).
LITTLE GOLDSTAR rudbeckia
This plant seems to correct the 'cons' of GOLDSTRUM. i.e. LG is quite compact and no blight or any other leaf issues as I had often got with Goldstrum. LG bloomed early and lasted very long.
BLUE HEAVEN FLUTTERBY buddleia :
I obtained the spindly specimen of a plant in early June and in the ground it went right away. It grew rapidly and by the end of June it had already begun to bloom and this continued into October. It's final size this season was a nicely proportioned 3' by 3'.