Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
A bit of scratched up grayness. Always good.
Source Dmitry
A seamless paper background colored in pale yellow.
Source V. Hartikainen
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
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
I’m starting to think I have a concrete wall fetish.
Source Atle Mo
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Seamless Prismatic Geometric Pattern With Background
Source GDJ
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim