I haven’t used it yet, but it will only be wise to link to Feed Wrangler for the majority of people showing up here in search of alternatives to Google Reader.
I heard of feed wrangler a few days back from Shawn blanc and I was curious to find out more about it and read this review of it by Viticci.
From the review, Feed Wrangler does feel like it is robust and has been built to last with a business model. You should read the review by Viticci if you are looking for an alternative for Google Reader.
For me though, i would prefer to run my servers and will be switching to Fever shortly.