The original enhanced with one of Inkscapes's filters.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
Colored maple leaves scattered on a surface. This is tileable, so it can be used as a background or wallpaper.
Source Eady
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
Black And White Floral Pattern Background from PDP.
Source GDJ
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Sharp but soft triangles in light shades of gray.
Source Pixeden
A seamless background texture of old cardboard.
Source V. Hartikainen
The image depicts a seamless pattern of the design which includes a stylized lotus and a stylized crane.I referred to the original image in a book which is into public domain.
Source Yamachem
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Sometimes you just need the simplest thing.
Source Fabricio
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Prismatic Triangular Background Design Mark II 5
Source GDJ