Depends. Effects for motion graphics or for film?
As for motion graphics, I personally think that the Stylise effects are the best. Still, depends on your motion graphics visual style..Retro / Pop Art, Clean and Futuristic, Abstract, old looking, etc. Thing is, Ramps, circles, borders, glows and transitions are commonly used to create Futuristic effects (in motion graphics) while Roughen Edges, Color Emboss, and etc. etc. are often used for Pop Art.
Bottom line, I think it’s impossible to ask someone to make a list of the top ten effects that will produce something cool out of nothing. “Art for art”. There are techniques, etc. but if you place the wrong effects in the wrong place at the wrong time, your animation won’t be “cool” at all. Personally, all (or 99%) of the effects in AE are cool. You just need to know how to use them effectively. This recquires art and AE experience. To me, both are essentials.
That’s how I see it.
Justin Productions
Tangerin01@hotmail.com
Adobe After Effects 6.5 Professional