I've tried a few and never been happy with any. Costs are generally high for the better feeds and they aren't that much better than just watching twitter or other news outlets.
A few I've tried:
Ransquawk
Tradethenews
Flyonthewall
Benzinga
I wasn't really that impressed with any of the services listed above.
Note: If you have a TDAmeritrade account with ThinkorSwim (TOS) software access, you can access the Benzinga audio for free in their audio chat section. There are also some other free audio services inside TOS.
If I were to recommend any of the above services I mentioned, I'd say Tradethenews is the best but its also the most expensive and most difficult to get access too (they 'screen' their customers').
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I use Talking Forex, already mentioned in the thread. Despite the name, they actually announce news and economic data releases for the most important markets, such as European and US equities indices and bonds, Oil as well as currencies.
I consider them pretty good although I am unable to make comparisons as I've never used others. Occasionally (once a week on average) the audio service may have issues but generally they are resolved quickly.
EDIT: I forgot to mention, on top of the audio feed there is a news feed on the website which keeps running overnight and covers Asia as well.
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