they're much better, well, not the 360/PS3 one, but most on the PS2. Budokai 2 is on a 2D plane, both are good; Budokai Tenkaichi 3 is an open 3D arena, also good. There are also the Supersonic Warrior games for GBA and DS that play like Psychic Force that are fun. The only good PS1 Dragon Ball game never came out in America and it's Legends, which is kind of a fighting game, but not really; it's hard to explain properly. Recently there was also a Dragon Ball Zelda style game that came out for the DS that's enjoyable.
The biggest problems with Dragon Ball games is how cheap they are with them. It's like, the first games in the series always go back to having 20 characters and only covering a small arc when the last game in the previous series had 100 or so. Dragon Ball Budokai Tenkaichi 3 had so many characters from Dragon Ball to Dragon Ball GT, but Burst Legend on 360/PS3 only had like 20 or so from the first half of DBZ.