[Nexus 7 Themes and Apps] brfsa:
I've been trying so many ebook readers for many years of different devices. So, here is my review:

I've tried about 12 ebook readers, but I will mention just the most popular ones.

I was using Aldiko for a while. It seems to be the one of the older apps, has a lot of good features, like night mode, text size, nice shelf view (which is a bit slow).

Then I tried Cool Reader, did not like it, found it slow.

Bluefire, good for PDF (but now I learned to convert from PDF to epub with Calibre, so uninstalled Bluefire).

Kindle app, way too basic and limited.

Power Reader, can't use it, FC all the time.

Moon+ reader, it has a nice shelf, and many settings to customize the reading mode, font size, color, margins, etc. many page flipping effects. if not the most customizable ebook reader I've tried.

It supports the tablet mode status bar (you know the bottom status bar, need to change your DPI to 160), It supports calibre Net library.

Very Polished and complete ebook reader. Just the Shelf view is a bit slow, and the cover are only loaded once you open the ebook. Pro version has excellent features and not that expensive.

This reader is absolutely the best you can get in the market. Market

FBReader, a very basic reader which I find it great for reading. I like that It has many advanced options and customizations for the ebook rendering. it supports tablet status bar too. It does not have a shelf view, the ebook browsing mode is just a list, which works ok for me.

it's quite fast and works perfect for my nexus 7. Supports Calibre net library.

Market

Both FBreader and Moon+ let me customize about everything I want, specially set the borders to use maximum size of the screen.

After reading this thread I tried out Mantano. It's a nice piece of software. It looks just so good, but after trying it out for a while I found that it only has a good look, but not many customization like FBreader and Moon+. There is no customization for the font settings and margins for the free version, I did not try the paid version.

it does look great, and the cloud feature is good, but you have to pay of course.

Basically, Moon+ Reader Free has most of the features of Mantano Premium paid version. Since all readers I mentioned here are free. Moon reader does not look so "nice" like the others but it has so many more features and customizations than any other reader out there.

So after all, I recommend Moon+ for full featured reader, or FBreader if you want a fast and light reader but still very powerful, and of course if you like to customize the and make it your own styled theme e-reader.

If you dont care about customization and just want to read a book, then any reader is just fine, Mantano might be your best shot after all.

Edit:

I recommend using Calibre library on the desktop computer if you have many mixed epub/mobi/pdf ebooks.

With calibre you can convert the books between mobi, epub and pdf, keeping all the versions. then you can export your epub version to android or ipad, or export the mobi the kindle. it can download covers and book information, and act as a network library servers.

ps: if you like my review, press thanks :D