Yeah. There are a some worthwhile games on the PS1, but the vast majority of them have superior versions on other systems. The only PS1 exclusive I'd consider a must-play game is Final Fantasy 7. Jedi Power Battles is definitely not worth the effort of tracking it down.
The other mega-huge PS1 game, Symphony of the Night, was ported to the XBoxLiveArcade last year and from my understanding runs much better off a hard-drive than a PS1 disc.