From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
A nice and simple white rotated tile pattern.
Source Another One
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
A free pink background pattern.
Source V. Hartikainen
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern formed from miutopia mug remixes on a tablecloth.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton