Alternate Java GUI Frameworks

Question

I am making a small game number game in Java (Nim) in OS X and was thinking about trying to make the GUI interface of the game using something other than Swing. I looked at SWT, but I read somewhere that SWT has some problems with OS X. I also looked at GTK+ bindings for Java, but I am not sure if that's a good choice either. Do you guys have any suggestions for a good Java GUI Framework that would look good and be compatible with OS X ?

Thanks