I just finished writing a review of Xero on trustradius.com and thought it might be nice to share it here. Xero isn't perfect (yet), but in my opinion, it's definitely the best on the market. Read what I have to say about it, including a short explanation about why I prefer Xero to QuickBooks Online.
In case you want more QBO vs. Xero reading, here is also a link to my post from a year ago that had a few people up in arms as well as my post on Sleeter's blog a couple of months ago that seemed to raise Intuit's interest. In both cases, you'll want to read through the comments.