I currently have a '93 BMW R1100R (I will need to sell as I can no longer ride) hands down the best handling, smoothest and fastest (light to light or top end) bikes I have ever ridden, (including my Kaw KZ1000 and Yamahah 650 Turbo) It is incredible.
My wife has a 1200 Sportster with the high cams (I know its just a Sportster but it has a he11 of an engine) and she wont ride it anymore after having ridden the beemer! My favorite for curve burning though was my Yamaha Seca 550, that thing could g=handle curves like nobody's business.