60º lines #25
 Light  CC BY-SA 3.0

Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.

Source Atle Mo

 More Textures
Visual illusion #2586
 Grid  CC 0

The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Background pattern 112 #263
 Fabric  CC 0

A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.

Source Firkin

Retro Circles Background 4 No Black@2X #423
 Dark  CC 0

Retro Circles Background 4 No Black

Source GDJ

Prismatic Groovy Concentric Background 3@2X #458
 Noise  CC 0

Prismatic Groovy Concentric Background 3

Source GDJ

Retro Squares Background 4@2X #419
 Dark  CC 0

Retro Squares Background 4

Source GDJ

WaveCut #75
 Light  CC BY-SA 3.0

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

Source Ian Soper

Prismatic Dots Background 7 #513
 Dark  CC 0

Prismatic Dots Background 7

Source GDJ

Paisley Background #495
 Light  CC 0

Paisley Background

Source GDJ

Background pattern 250 (colour 4) #2168
 Blue  CC 0

To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Prismatic Hexagonalist Pattern No Background #390
 Light  CC 0

Prismatic Hexagonalist Pattern No Background

Source GDJ

MBossed #193
 Grid  CC BY-SA 3.0

Embossed lines and squares with subtle highlights.

Source Alex Parker

Real Carbon Fiber@2X #287
 Carbon  CC BY-SA 3.0

Carbon fiber is never out of fashion, so here is one more style for you.

Source Alfred Lee

Colorful Floral Background@2X #480
 Noise  CC 0

Colorful Floral Background

Source GDJ