Cross-Processing in E6 Chemistry

While my preference has always been either black and white prints or colo(u)r transparencies, I have, on occasion, done a bit of shooting with both colo(u)r and, more recently, black and white infrared films. In that vein, I would like to give cross-processing a go. So, my question is: Which of the C-41 films currently on the market (or would expired C-41s give more unusual results?), processed in E6 chemistry (a transparency is my preferred end-product), would provide the most dramatic colo(u)r images?