as i've mentioned in another topic:
MobileRSS HD. It allows you to sync with google reader (rss). Nothing notable if you read the description or see the screenshots:
Other apps can do it or looks better you'd say. But it's the usability that counts.
It syncs and downloads in the background. So you can continue reading your feeds, while it updates on the fly.
Unlike certain apps where you have to wait till the sync is done.
It also allows offline reading if you let it run while connected.
Another important aspect is, it download images from articles smartly. IE. you're reading article 1? then it'll download images for article 2 first, so when you go to the next article, it's already in cache. (although it seems to have trouble rendering at portrait. It's slower to "load and show" the image. On landscape it's there instantly.
MobileRSS has by far the most integration with 3rd party services (twitter, instapaper, readitlater, etc)
see this screenshot:
Of course, for comics I like ComicZeal4 http://www.bitolithic.com/comic-zeal-v4
It's initial version were kinda bland and not really user friendly. But after 8 revisions, it has evolved to a robust, user friendly app.
What's so special new version?
Magic background color: if a page isn't fullscreen, the background color will be changed into the color of the margincolor of the page. IE. if the margins were white, the background will be filled with white. If black, it'd be filled with black. It seems like nothing special, but it does increase the reading experience a lot.
Also very important, it's OS-globally referenced as an app for cbr/cbz/zip/rar-files. Meaning that you can open these files from any other app into comiczeal (download through dropbox, read in comiczeal)
It allows you to lower the brightness, just like ibooks.
It'll popup the next-chapter/comic when you're finished with one, so you can continue reading.
Remembers where you're left off.
But there is one itunes-problem... when transferring files through itunes USB-transfer, itunes would scan the app's docdir for the filesizes. After 10GB worth of decompressed comicfiles (IE a lot of images), the scanning takes a very long time. So now I have to wait like 5 minutes before I can drag and drop files into the app through itunes. (and after each file transfer, itunes will try to update the diskusage, and thus rescans... luckily you can just click another itunes options like "music" so it does not rescans anymore)
Nevertheless, it's not usable situation. That's why I only drop collections of comics into cz. For updates/daily single chapters, I use another comicapp: arcreader.
It's not as sophisticated as comiczeal, but it's the second best app as the controls are quite similar. Also it's free.