A 3 cushion cue has a conical taper.
There are an infinite amount of tapers out there, as any deviation from a basic taper, by definition, creates a new taper. Hence, "modified pro taper," etc.
If you use the search feature in the "ask the cuemaker" section, you'll find a lot of questions and answers about tapers, and also read the many definitions of what one would think were "standard" tapers.
You've just gotta find what you like.
~Beau