The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
The base gradient edited so now more details are rendered.
Source Lazur URH
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Prismatic Snowflakes Pattern 2 No Background
Source GDJ