Western style dresses
Styles inspired by Western style dresses, but with Islamic standards’ coverage.

Shukr Islamic Clothing
HIWI Fashion 
Imaan Collections

Denim dresses
Called ‘abaya’ and ‘jilbab’ on these sites, but I think it could be called a dress, too. If I were looking for a denim dress, I would like to see these.

Al-Farah
Crescent Moon Boutique

Jumpers
American English (not British English) usage of the term meaning an over-the-head dress that must have a shirt worn under it because it has no sleeves.

Shukr Islamic Clothing
AlHediya.com 
Artizara

Sheaths
Long dresses, but sleeveless; intended to be worn with something over to cover the arms.

AlHediya.com 

Modest housedresses
Dresses to wear in the house ;)

AlHediya.com 
Purely Elegant
Love Unspoken

Formal dresses
Formal designs of Western-style dresses, but with Islamic standards’ coverage.

Shukr Islamic Clothing
Orientwear
Artizara
Abiye
Primo Moda™