Graphically, I am not sure yet. But if we are talking about the level setups, I\'d have to go with Tekken 4.
Virtua Fighter 4 levels are "rings." Some levels have walls on the sides of the rings, some levels just let you drop out of them for ring outs, and some levels make you force an apponent through a wall to get a ring out. But in the end, they are all just rings. From the review I read at IGN, the backgrounds are beautiful, but not being able to reach them sucked.
In Tekken 4, the levels vary in size and shape, and they also have breakable objects. Some levels are long and skinny (the garage), some are huge and free-roaming(the airport). Tekken 4 also has something that the VF series got rid of, elevation changes in the levels.
I still think it\'s a little too early to judge this though, because I want to see both in person before I make a decision.