I say the top 3 right now is the following:
Byline
Feeds
Newsstand
The difference between the three is simple the following.
1. If you use Google reader, newsstand is out of the question, in terms of sync'ng with it. Yes, you can import your feeds into Newstand but it's more of a standalone RSS reader.
2. Newstand is by far the best looking app, and functionality wise, very robust, however, once again it's a standalone application.
3. If you're a Google Reader user, then Byline and Feeds are your best bet. Between the two, there are subtle differences which at some point in the future will probably match each other in functionalities. They both sync with Google Reader, both application can "STAR" an item, one can allows you to add/sync NOTES, both allows you to email the Feed, etc.
The bottom line is that both are relatively competitive and depending on the user, will choose one over the other and be happy with it. As stated before, there will be some point where both application will incorporate a functionality that one has over the other and will probably be a toss up based on the look and feel and not Functionalities. (that's just how these application in the appstore evolves).
Lastly, if you really want to compare apples to apples, Byline is a bit ahead of Feeds in that from a functionality perspective have tackled most "sync" capabilities than Feeds and combined with "Offline mode" that Byline has, makes it relatively top notch. However, that is not without consequences. Feeds, on the other hand, is faster than Byline. (Due to the offline capabilities of Byline that requires "extra" polling or whatever you want to call it).
So as you can see, each user will have to choose what's most important to them at this point in time.
Another example I should throw out there is that Byline doesn't have subfolder structure. In other words, if you have your Feeds in folders such as below...
Technology
>>>>>>>Macrumors
>>>>>>>Engadget
In Byline, the feeds from Macrumors and Engadget are mixed in versus the ability to drill down with subfolders that Feeds have accomplished. This is an annoyance to me simple the fact that if I want to read "macrumors" feeds, there is really no easy way.
BUT....
As part of app evolution, this is going to be addressed by Byline in their next release (sometime in April, hopefully).
Confused yet. hahaha.
What about the other RSS feeds such as iNews, Newsgator app, etc. ?
They all perform well but not as robust and as refined as the top 3 I mentioned. Of course, you will have happy users for these other applications but in a general consensus (I say this loosely), the top 3 is what I mentioned above.