Paven@2X #297
 Grid  CC BY-SA 3.0

A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.

Source Josh Green

 More Textures
Rubber Grip #101
 Dark  CC BY-SA 3.0

A very slick dark rubber grip pattern, sort of like the grip on a camera.

Source Sinisha

WaveCut@2X #76
 Light  CC BY-SA 3.0

If you like it a bit trippy, this wave pattern might be for you.

Source Ian Soper

Carbon Fiber@2X #4
 Carbon  CC BY-SA 3.0

A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.

Source Atle Mo

Prismatic Chevrons Pattern 5 With Background #469
 Dark  CC 0

Prismatic Chevrons Pattern 5 With Background

Source GDJ

Background pattern yellow #1999
 Yellow  CC 0

Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Background pattern 2 #221
 Noise  CC 0

A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.

Source Firkin

Elegant Grid #316
 Wall  CC BY-SA 3.0

This is a hot one. Small, sharp and unique.

Source GraphicsWall