two good choices
I always have one of the two below pocketed:
The wonderful CRKT M-16 small version. It does have a clip, but it is removable, though you don't have to. It deploys instantaneously with a choice of flipper, thumb stud, or wrist flick. It is delivered very sharp and maintains its edge. Slim, light, pocketable. $30-50 I think.
AG Russell One-hand knife, kydex (or some such handle material). This is my all-time favorite. I've lost them and bought them again. Not big, but instantaneous deployment with practice. Use a wrist flick or snap open ala with the Spyderco-type hole in blade. Do NOT use the hole as a thumb stud. This thing is so @#$%^& ing sharp, it will cut you to the bone [the voice of experience]. The knife is also available with a nice kydex neck sheath and chain. It is very, very light and thin. Some people might not understand its picklock, so if you loan it out, tell them you'll close it. About $50.
A cc knife does not need size. A knife is not a deterrant unless you want to carry a Bowie. You do not brandish a defense blade, because when you do, you have to defend yourself and the knife. And why would you need speed, if all you want to do is wave it around? A blade is an up close and personal thing.