Well, my personal favorite character in Tekken 3 is Hwoarang. As I come from a martial arts background, I like to use the Tae Kwondo kicks like the butterfly tornado kick to knock the opponents out. Again, that's a debate whether TaeKwondo works in a real fight or not, but it surely works in Tekken.
In the same way, my second favorite player in Tekken 3 is Yoshimitsu due to the fact that he can end the game with one hit using the sword. Again the weakest in terms of physical capabilities but full of supernatural powers, True Ogre is a character that you should not ignore. He can finish all of his opponents without touching them and breathing fire by flying in the air. However, it does not works for Gon as he has fire-resistant capabilities.
On the other hand, for players who like to brawl in close combat, King and Paul are the best choices. The 16-hit grappling combo by King, which I would like to call "16 Moves of Doom" does not let the opponent escape until they pass out. That's my personal favorite brawler in Tekken 3 who can perform all sorts of pro wrestling moves. Most notably, King can perform a DDT, Cesaro Swing, Figure Four Leg Lock, Back Breaker, and even Tombstone Piledriver.
So these are the best players in Tekken 3. But it always depends upon the fighting that you like to entertain with. For example, a few people like Capoeira, so they select Eddy Gordo whereas kung fu fans choose Law, Xiaoyu, or Lei. Every player in Tekken 3 is strong enough to knock off their opponents, it's just that you have to be familiar with the moves.