Here are mine:
* In terms of design
- good flow
- in your face effects
- clever transitions
- surprises/jokes
- funny texts
- some attitude
* About gfx
- sweet pixeled stuff
- stylish logos
- carefully chosen colours
- (I miss all those things in my demos

)
* Effects
- I sometimes like 3d but can be easilly bored with them
- So I love more 2d effects. Or maybe something interesting done with 3d
* oldschool effects I love from soft demos:
- plasmas, rotozoomers, distortions, sphere and other mapping (I just can't get enough of em

- 2d water, bump, radial blur, all kinds of blur, feedback effects. Especially those which can make them look awesome (it's kind tricky to make radial blur look good for example)
- fractals. Fewer demos utilise them in comparison to the other effects. A demo with good use of fractals stays in mind forever (verses by emf, live evil by mandula and more)
- VOXELS!!! love em.. especially those beautiful landscapes.
- demos that combine these effects in clever ways
- Shiny, phong shaded, environment map, glittering 3d objects of the past. I don't know why we don't see enough of them with modern 3d hardware? Maybe it's considered kitch or something of the past and it's avoided? I prefer a highly detailed, great looking, shiny 3d object in front of a beautiful background or 2d effect, combined somehow,.. than just a full blown 3d engine.
* Music
- Just a matter of taste. Sometimes I like fast paced electronic music (especially if it's synced greatly with the visuals) but sometimes I can enjoy more emotional, slow paced or abstract types of music. Depends..
* Hardware
- If it runs on the C64 or a GBA or anything low powered it's a bonus for me (but that's just a personal preference) because I try to feel of the challenge and mastery of something running so smooth and still look good on a limited hardware. There are effects that are in such a way improved that even with the low res or dithered blocks they still look good enough and smooth. Those people especially on the C64 make older versions of master effect look better every year.
* A crappy demo would just take these effectsand make mediocre versions that are worse than those in the past.