Which preview for the brushes is better?

1:
http://img206.echo.cx/img206/2079/grunge1large7bp.jpg

OR

http://img143.echo.cx/img143/2685/grunge15km.jpg

2:
http://img143.echo.cx/img143/475/brushes4ue.jpg

OR

http://img143.echo.cx/img143/3293/abstract17ou.jpg