Hm. I don't know what exactly you dislike about the gameplay. But in general, I'd say to make a good third person game you need great animations on the player characters, smooth movement (no sliding around, make sure each step the character takes looks right) and good controls which make the player feel like he's moving a "mass". For example, when the character is standing and then starting to run, make him accelerate. Don't go from 0 speed to top speed instantly. Same deal with curves: when you rotate, don't rotate instantly but have a little phase of acceleration. Of course you mustn't overdo this, because it would be frustrating if the character wouldn't rotate fast enough.
What also makes the game real fun to play is if the character leans realistically while running around corners. Lean a little to the left on a left corner and to the right on a right corner.

If you have a camera somewhere, why not videotape yourself doing some of the moves you want in the game? Maybe even get a friend and try to film over-the-shoulder while you're doing them?
You might find that camera rolling could also be interesting: when the character rotates you can make the camera roll about 2 or 3 degrees into that direction.

Good recoil animations would add to the game as well. The player should pull back his gun, the stronger the gun, the more it should push his torso back/up.

Of course you mustn't overdo any of these effects so you don't lose speed in gameplay.

My 2 cents...