The first two covers are exact lookalikes: The Age of Shiva by Manil Suri and La part manquante by Christian Bobin (originally in French, translated as The Missing Part).
The other two pairs are very similar: two different covers for What Girls Learn by Karin Cook, which look like The Chosen One by Carol Lynch Williams (down to the pink title!) and The 19th Wife by David Ebershoff, both of which happen to be novels about polygamy.
I think my favourite cover is The Chosen One, but that may be because I read the cover story, which explains the significance of this image, over at Melissa Walker’s blog. (I do think its similarity to What Girls Learn is uncanny!)
I recently won a copy of The Chosen One from Natasha at Maw Books Blog (yay!), so I should be reviewing it sometime this summer.