I'd agree with siaan312 on the surface. However, the 5900X has additional L3 cache that the 5800X does not, which can improve gaming performance somewhat. If its worth it over the 5800X is a whole other discussion though.
But with how cheap the 5900X now, at $350, you can't go wrong with it.
Depends on budget of course...but a 5800X3d would be more likely to provide significant help with CPU limited games. This CPU seems to hang in really well with 7600X CPU's (and maybe 7700X too, based on comments only) in launch reviews. In some games it even beats it pretty handily...of course, those are games that benefit most from CPU threads and cache but your game could be similar.