From my point of view, slides offer the greatest total number of output options. Yes, the range of the scene has to be just right and the exposure latitude is smaller, but notwithstanding those constraints, which are really minor if a person knows what he/she is doing with a meter, slides can be used to...
1) ... generate enlarged b&w negs in one easy step
2) ... make polaroid/fuji image and/or emulsion transfers (which is much more controllable and reproducible than shooting straight to the instant film)
3) ... make ilfochromes
4) ... scan and get very, very smooth and high resolution results for hybrid techniques
5) ... relish the slides on a light table
6) ... last but not least, impress the living daylights out of the audience of a slideshow, most members of which will have never seen anything better than 800 pixel output from powerpoint run through a low-end projector